MCQ Questions for Class 7 Maths Algebraic Expressions Quiz 2

State True or False:
On subtracting

$x^3-4x-1$ from

$3x^3-x^2+6$ , the answer is

$2x^3-x^2+4x+7$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 3{ x }^{ 3 }-x^{ 2 }+6\quad -(\quad { x }^{ 3 }-4x-1)\\ \Longrightarrow (3-1){ x }^{ 3 }+(-1+0){ x }^{ 2 }+(+4)x+(6+1) =2{ x }^{ 3 }-x^{ 2 }+4x+7$

State True or False:
Addition of

$-2ax-6by+4cz, \ 4by-14ax, \ 9cz-4ax-6by$ is

$-16ax-8by+13cz$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad variables\quad directly,\\ -2ax-6by+4cz\quad +\quad 4by-14ax\quad +9cz-4ax-6by\\ =-16ax-8by+13cz\\$

State True or False:
On subtracting

$a-b-2c$ from

$4a+6b-2c$ , the answer is

$3a+7b$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad variables\quad directly\quad \\ a-b-2c\quad -\quad 4a-6b+2c\\ =3a+7b\\$

State True or False:
On subtracting

$3a-5b+c+2d$ from

$7a-3b+c-2d$ , the answer is

$4a+2b-4d$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad variables\quad directly\quad \\ 7a-3b+c-2d\quad -\quad 3a+5b-c-2d\\ =4a+2b-4d\\$

State True or False:
Addition of

$13ab-9cd-xy, \ 15cd-7ab, \ 6xy-3cd$ is

$6ab+3cd+5xy$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ \Longrightarrow (13-7)ab+(-9+15-3)c+(-1+6)=6ab+3cd+5xy$

State True or False:
On subtracting

$4xy^2$ from

$3xy^2$ , the answer is

$-xy^2$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad variables\quad directly\quad \\ { 3xy }^{ 2 }-{ 4xy }^{ 2 }\\ ={ (3-4)xy }^{ 2 }\quad =\quad { -xy }^{ 2 }\\$

State True or False:
Addition of

$x^3-x^2y+5xy^2+y^3, \ -x^3-9xy^2+y^3, \ 3x^2y+9xy^2$ is

$2x^2y+5xy^2+2y^3$ .

0%
True
0%
False

Explanation

$\quad We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ \Longrightarrow (1-1){ x }^{ 3 }+(-1+3){ x }^{ 2 }y+(5-9+9)xy^{ 2 }+(1+1)y^{ 3 }=2{ x }^{ 2 }y+5xy^{ 2 }+2{ y }^{ 3 }$

State True or False:
On subtracting

$-2x^2y+3xy^2$ from

$8x^2y$ , the answer is

$10x^2y-3xy^2$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad variables\quad directly\quad \\ { 8x }^{ 2 }y-{ 3xy }^{ 2 }+2x^{ 2 }y\\ ={ (8+2)x^{ 2 }y-3xy }^{ 2 }\quad =\quad { 10x^{ 2 }y-3xy }^{ 2 }\\$

State True or False:
Addition of

$a^6-4a^4+6a, \ 5a^6+5a^4+6a, \ 12a^6-10a$ is

$18a^6+a^4+2a$ .

0%
True
0%
False

Explanation

$We\quad can\quad add\quad the\quad coefficient\quad of\quad like\quad powers\quad directly,\\ { a }^{ 6 }-{ 4a }^{ 4 }+6a\quad +\quad { 5a }^{ 6 }+{ 5a }^{ 4 }+6a\quad +\quad { 12a }^{ 6 }-10a\\ =(1+5+12){ a }^{ 6 }+(-4+5){ a }^{ 4 }+(6+6-10)a\\ =18{ a }^{ 6 }+{ a }^{ 4 }+2a\\$

State True or False:
On subtracting the sum of

$5y^2+y-3$ and

$y^2-3y+7$ from

$6y^2+y-2$ , the answer is

$3y-6$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad and\quad subtract\quad the\quad coefficients\quad of\quad like\quad variables,\\ 6y^{ 2 }+y-2\quad -\quad( 5y^{ 2 }+y-3\quad+\quad y^{ 2 }-3y+7)\\ \Longrightarrow (6-5-1){ y }^{ 2 }+(1-1+3)y+(-2+3-7)\\ =3y-6$

How much more than

$2x^2+4xy+2y^2$ is

$5x^2+10xy-y^2$ ?
State True or False: The answer is

$3x^2+6xy-3y^2$ .

0%
True
0%
False

Explanation

$We\quad will\quad subtract\quad the\quad 2\quad to\quad find\quad the\quad difference,\\ We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 5x^{ 2 }+10xy-y^{ 2 }\quad -\quad (2x^{ 2 }+4xy+2y^{ 2 })\\ =3x^{ 2 }+6xy-3y^{ 2 }$

How much less than

$3a^2-6$ is

$2a^2+1$ ?
State True or False: The answer is

$a^2-7$ .

0%
True
0%
False

Explanation

State True or False:

$x=6a+8b+9c$ ;

$y=2b-3a-6c$ and

$z=c-b+3a$ ; then

$x+y+z$ is

$6a+9b+4c$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ x=6a+8b+9c;\quad y=2b-3a-6c;\quad z=c-b+3a\\ x+y+z\quad =6a+9b+4c$

State True or False:
On subtracting

$a^2+ab+b^2$ from

$4a^2-3ab+2b^2$ , the answer is

$3a^2-4ab+b^2$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 4a^{ 2 }-3ab+2b^{ 2 }\quad -\quad( a^{ 2 }+ab+b^{ 2 })\\ \Longrightarrow (4-1){ a }^{ 2 }+(-3-1)ab+(2-1)b^{ 2 }\\ =3a^{ 2 }-4ab+b^{ 2 }$

State True or False:
On subtracting

$-3x^3+4x^2-5x+6$ from

$3x^3-4x^2+5x-6$ , the answer is

$6x^3-8x^2+10x-12$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 3{ x }^{ 3 }-4x^{ 2 }+5x-6\quad -\quad( { -3x }^{ 3 }+4x-5x+6)\\ \Longrightarrow (3+3){ x }^{ 3 }+(-4-4){ x }^{ 2 }+(5+5)x+(-6-6)\\ =6{ x }^{ 3 }-8x^{ 2 }+10x-12$

State True or False:
On subtracting

$cab-4cad-cbd$ from

$3abc+5bcd-cda$ , the answer is

$2abc+3cad+6bcd$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 3abc+5bcd-cda\quad -\quad( cab-4cad-cbd)\\ \Longrightarrow (3-1)abc+(-1+4)cad+(1+5)bcd\\ =2abc+3cad+6bcd$

State True or False:
On subtracting

$-m^2+m+4$ from

$2m^2+m+1$ , the answer is

$3m^2-m-1$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ 2m^{ 2 }+m+1\quad -\quad (m^{ 2 }+m+4)\\ \Longrightarrow (2-1){ m }^{ 2 }+(1-1)m+(1-4)\\ =m^{ 2 }-3$

State True or False:
On subtracting

$6a+3$ from

$a^3-3a^2+4a+1$ , the answer is

$a^3-3a^2-2a-2$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ a^{ 3 }-3a^{ 2 }+4a+1\quad -\quad( 6a+3)\\ \Longrightarrow (1)a^{ 3 }+(-3){ a }^{ 2 }+(4-6)a+(1-3)\\ =a^{ 3 }-3a^{ 2 }-2a-2$

Add:

$2x+y+z$ ;

$-x+2y+2z$ and

$x-y-z$

0%
$2x+2y+2z$
0%
$3x+5y+z$
0%
$3x-3y-z$
0%
None of these

Explanation

Sum of

$(2x+y+z),$

$(-x+2y+2z)$ and

$(x-y-z)$ is:

$=\displaystyle \left( 2x+y+z \right) +\left( -x+2y+2z \right) +\left( x-y-z \right)$

$=(2x-x+x)+(y+2y-y)+(z+2z-z)$

$=2x+2y+2z$

$=2(x+y+z)$

The sum of

$\displaystyle 3ab, -8ab$ and

$5ab$ is equal to

0%
$\displaystyle 10ab$
0%
$\displaystyle 16ab$
0%
$\displaystyle ab$
0%
$0$

Explanation

We have to find sum of

$3ab, -8ab, 5ab$

$\therefore$ required sum is

$=\displaystyle 3ab+\left( -8ab \right) +5ab$

$\displaystyle =8ab-8ab=0$

Add the given expressions

$5m+0.3n-1.2t; \, \, 0.23m - 2.8t + 4n$

0%
$5.3m + 4.13n-4t$
0%
$5.23m + 4.3n-4t$
0%
$52.33m + 0.43n-4t$
0%
$5.23m + 43n-4t$

Explanation

$5m+0.3n-1.2t+ 0.23m-2.8t+4n$

$=5m+0.3n-1.2t+0.23m+4n-2.8t$

$=5.23m + 4.3n-4t$

State True or False:

$x=6a+8b+9c$ ;

$y=2b-3a-6c$ and

$z=c-b+3a$ ; then

$2x-y-3z$ is

$6a+17b+21c$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ x=6a+8b+9c;\quad y=2b3a6c;\quad z=cb+3a\\ 2x-y-3z\quad =2(6a+8b+9c)\quad -\quad (2b-3a-6c)\quad -3(c-b+3a)\\ =6a+17b+21c$

State True or False:

$x=6a+8b+9c$ ;

$y=2b-3a-6c$ and

$z=c-b+3a$ ; then

$x-y+z$ is

$12a+5b+16c$ .

0%
True
0%
False

Explanation

$We\quad can\quad directly\quad add\quad the\quad coefficients\quad of\quad like\quad variables,\\ x=6a+8b+9c;\quad y=2b-3a-6c;\quad z=c-b+3a\\ x-y+z\quad =12a+5b+16c$

State True or False:

$x=6a+8b+9c$ ;

$y=2b-3a-6c$ and

$z=c-b+3a$ ; then

$3y-2z-5x$ is

$-45a-32b-65c$ .

0%
True
0%
False

Explanation

$x=6a+8b+9c;$

$y=2b-3a-6c$

$\&$

$z=c-b+3a$

The value of

$3y-2z-5x$ will be,

substitute

$x$

$\&$

$y$

$\&$

$z$ in the expression,

$=3\left( { 2b-3a-6c } \right) -2\left( { c-b+3a } \right) -5\left( { 6a+8b+9c} \right)$

$=6b-9a-18c-2c+2b-6a-30a-40b-45c$

$=45a-32b-65c$

Hence, the answer is true.

If we take away

$\displaystyle -8abc$ from

$\displaystyle -7abc$ , then the result is equal to

0%
$\displaystyle abc$
0%
$\displaystyle 15abc$
0%
$\displaystyle -abc$
0%
$\displaystyle -15abc$

Explanation

We have to just subtract

$-8abc$ from

$-7abc$

$=\displaystyle \left( -7abc \right) -\left( -8abc \right)$

$\displaystyle =-7abc+8abc$

$= abc$

What is the sum of

$\displaystyle \left( 4a+5b \right) ,\left( -6a+2b \right) ,\left( 7a-6b \right)$ ?

0%
$\displaystyle -5a+b$
0%
$\displaystyle 5a+b$
0%
$\displaystyle 5a-b$
0%
$\displaystyle -5a-b$

Explanation

We have to find sum of

$(4a+5b), (-6a+2b), (7a-6b)$

$\therefore$ required sum

$=\displaystyle \left( 4a+5b \right) +\left( -6a+2b \right) +\left( 7a-6b \right)$

$\displaystyle =\left( 4a-6a+7a \right) +\left( 5b+2b-6b \right)$

$=\displaystyle 5a+b$

What should be added to

$6x^2-3xy+4y^2$ to get

$2y^2+xy-4x^2$ ?

0%
$-x^2-y^2+4y$
0%
$-10x^2-y^2+4xy$
0%
$x^2-2y^2+4x$
0%
$-10x^2-2y^2+4xy$

Explanation

Let the required expression be

$P$

$P=(2y^{ 2 }+xy-4x^{ 2 })-(6x^{ 2 }-3xy+4y^{ 2 })$

$=-4x^{ 2 }+2y^{ 2 }+xy-6x^{ 2 }+3xy-4y^{ 2 }$

$=-10x^2-2y^2+4xy$

Subtract

$6x+8y+4$ from the sum of

$4x-2y+3$ and

$2y-x+3$ ?

0%
$-x-8y-2$
0%
$-3x-8y+2$
0%
$-3x-y+1$
0%
$-x-8y+2$

Explanation

Consider,

$(4x-2y+3)+(2y-x+3)$

$=4x-2y+3+2y-x+3$

$=3x+6$

Subtracting

$6x+8y+4$ from

$3x+6$ we get,

$(3x+6)-(6x+8y+4)$

$=3x+6-6x-8y+4$

$=-3x-8y+2$

By how much is

$\displaystyle a^{4}+4a^{2}b^{2}+b^{4}$ more than

$\displaystyle a^{4}-8a^{2}b^{2}+b^{4}$ ?

0%
$\displaystyle 12a^{2}b^{2}$
0%
$\displaystyle -12a^{2}b^{2}$
0%
$\displaystyle 2a^{4}+2b^{4}$
0%
None

Explanation

$\displaystyle a^{4}+4a^{2}b^{2}+b^{4}$

$\displaystyle a^{4}-8a^{2}b^{2}+b^{4}$

$-$

$+$

$-$

$\displaystyle \overline{\underline{12a^{2}b^{2}}}$

$\displaystyle \left( p+q \right) -\left( p-q \right)$ is equal to

0%
$\displaystyle 2p+2q$
0%
$\displaystyle 2p$
0%
$\displaystyle 2q$
0%
$0$

Explanation

Given,

$\displaystyle \left( p+q \right) -\left( p-q \right) =p+q-p+q$

$=2q$
Hence simplified form of the given expression is

$2q$

CBSE Questions for Class 7 Maths Algebraic Expressions Quiz 2 - MCQExams.com

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Practice Class 7 Maths Quiz Questions and Answers

CBSE Questions for Class 7 Maths Algebraic Expressions Quiz 2 - MCQExams.com

0:0:1

Practice Class 7 Maths Quiz Questions and Answers

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