Class 8 Factorisation CBSE Questions & Answers

Class 8 · Factorisation

This is Mathematics Class 8 Factorisation CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Find the common factors of 6abc, \({\text{24}}a{b^{\text{2}}}\) and 12 \({a^{\text{2}}}b\).
  • A
    b
  • B
    6ab
    Correct
  • C
    a
  • D
    6
2
In expressions which have factors of the type (x + a) (x + b), remember the numerical term gives _______.
  • A
    ab
    Correct
  • B
    a
  • C
    \(\frac{1}{2}\)ab
  • D
    b
3
Factorise: \({q^{\text{2}}}\)– 10q + 21
  • A
    (q – 3)
  • B
    None of these
  • C
    (q – 7)
  • D
    (q – 3) (q – 7)
    Correct
4
Factorise: \({p^{\text{2}}}\)+ 6p – 16
  • A
    (p + 8) (p – 2)
    Correct
  • B
    None of these
  • C
    (p + 8)
  • D
    (p – 2)
5
Divide: 10y (6y + 21) \( \div \) 5 (2y + 7)
  • A
    y
  • B
    6y
    Correct
  • C
    8y
  • D
    6
6
Divide: \({\text{9}}{x^{\text{2}}}{y^{\text{2}}}\left( {{\text{3}}z-{\text{ 24}}} \right){\text{ }} \div {\text{ 27}}xy\left( {z-{\text{ 8}}} \right)\)
  • A
    x
  • B
    \(\frac{1}{2}\) xy
  • C
    xy
    Correct
  • D
    y
7
Divide as directed: \({\text{4}}yz\left( {{z^{\text{2}}} + {\text{ 6}}z-{\text{ 16}}} \right){\text{ }} \div {\text{ 2}}y\left( {z + {\text{ 8}}} \right)\)
  • A
    2z
  • B
    2z (z – 2)
    Correct
  • C
    (z – 2)
  • D
    None of these
8
Divide as directed: \({\text{5}}pq\left( {{p^{\text{2}}}-{q^{\text{2}}}} \right){\text{ }} \div {\text{ 2}}p\left( {p + q} \right)\)
  • A
    \(\frac{7}{2}q(p - q)\)
  • B
    \(\frac{3}{2}q(p - q)\)
  • C
    None of these
  • D
    \(\frac{5}{2}q(p - q)\)
    Correct
9
Find and correct the errors in the following mathematical statements. Substituting \(x = {\text{ }}-{\text{ 3 in}}{x^{\text{2}}} + {\text{ 5}}x + {\text{ 4}}\) gives \({\left( {-{\text{ 3}}} \right)^{\text{2}}}\)+ 5 (– 3) + 4 = 9 + 2 + 4 = 15
  • A
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\)+ 5 (–3) + 4 = 9 – 15 + 4 = –3
  • B
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\)+ 5 (–3) + 4 = 9 – 15 + 4 = –2
    Correct
  • C
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\) + 5 (–3) + 4 = 9 – 15 + 4 = –5
  • D
    None of these
10
Find and correct the errors in the following mathematical statements. Substituting \(x = {\text{ }}-{\text{ 3 in}}{x^{\text{2}}}-{\text{ 5}}x + {\text{ 4}}\)gives\({\left( {-{\text{ 3}}} \right)^{\text{2}}}\)– 5 ( – 3) + 4 = 9 – 15 + 4 = – 2
  • A
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\)– 5(–3) + 4 = 9 + 15 + 4 = 25
  • B
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\)– 5(–3) + 4 = 9 + 15 + 4 = 28
    Correct
  • C
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\)– 5(–3) + 4 = 9 + 15 + 4 = 23
  • D
    \({\left( {-{\text{3}}} \right)^{\text{2}}}\) – 5(–3) + 4 = 9 + 15 + 4 = 20
11
Find the common factors of the given terms: 36xy, 12y
  • A
    12
  • B
    12y
    Correct
  • C
    y
  • D
    None of these
12
Find the common factors of the given terms: \({\text{1}}0{{\text{x}}^{\text{2}}},{\text{ }}--{\text{ 18}}{{\text{x}}^{\text{3}}},{\text{ 14}}{{\text{x}}^{\text{4}}}\)
  • A
    \({\text{2}}{{\text{x}}^{\text{2}}}\)
    Correct
  • B
    None of these
  • C
    2x
  • D
    \({{\text{x}}^{\text{2}}}\)
13
Find the common factors of the given terms: \({\text{12}}{{\text{a}}^{\text{2}}}{\text{b}},{\text{ 15a}}{{\text{b}}^{\text{2}}}\)
  • A
    3ab
    Correct
  • B
    None of these
  • C
    ab
  • D
    3
14
Factorise: \({\text{9}}{{\text{x}}^{\text{2}}} + {\text{ 25}}{{\text{y}}^{\text{2}}} + {\text{ 3}}0{\text{xy}}\)
  • A
    \(\left( {{\text{3x }} + {\text{ 5y}}} \right)\)
  • B
    \({\left( {{\text{3x }} + {\text{ 7y}}} \right)^{\text{2}}}\)
  • C
    \({\left( {{\text{3x }} + {\text{ 5y}}} \right)^{\text{2}}}\)
    Correct
  • D
    \({\left( {{\text{3x }} - {\text{ 5y}}} \right)^{\text{2}}}\)
15
Factorise: \({\text{36}}{{\text{y}}^{\text{2}}}-{\text{ 36y }} + {\text{ 9}}\)
  • A
    9
  • B
    None of these
  • C
    \({\text{9 }}{\left( {{\text{2y }}-{\text{ 1}}} \right)^{\text{2}}}\)
    Correct
  • D
    \({\left( {{\text{2y }}-{\text{ 1}}} \right)^{\text{2}}}\)