ML Aggarwal Factorisation Check Your Progress Class 8 ICSE Ch-11 Maths Solutions. We Provide Step by Step Answer of Check Your Progress Questions for Factorisation as council prescribe guideline for upcoming board exam. Visit official Website CISCE for detail information about ICSE Board Class-8.
ML Aggarwal Factorisation Check Your Progress Class 8 ICSE Maths Solutions
Board | ICSE |
Publications | Avichal Publishig Company (APC) |
Subject | Maths |
Class | 8th |
Chapter-11 | Factorisation |
Writer | ML Aggarwal |
Book Name | Understanding |
Topics | Solution of Check Your Progress Questions |
Edition | 2023-2024 |
Factorisation Check Your Progress
ML Aggarwal Class 8 ICSE Maths Solutions
Page-202
Question 1. Find the HCF of the given polynomials:
(i) 14pq, 28p2q2
(ii) 8abc, 24ab2, 12a2b
Answer:
(i) 14pq, 28p2q2 (HCF of 14, 28 = 14)
HCF of 1 4pq, 28p2q2 = 14pq
(ii) 8abc, 24ab2, 12a2b
HCF of 8, 24, 12 = 4
HCF of 8abc, 24ab2, 12a2b = 4ab
Question 2. Factorise the following:
(i) 10x2 – 18x3 + 14x4
(ii) 5x2y + 10xyz + 15xy2
(iii) p2x2 + c2x2 – ac2 – ap2
(iv) 15(x + y)2 – 5x – 5y
(v) (ax + by)2 + (ay – bx)2
(vi) ax + by + cx + bx + cy + ay
(vii) 49x2 – 70xy + 25y2
(viii) 4a2 + 12ab + 9b2
(ix) 49p2 – 36q2
(x) 100x3 – 25xy2
(xi) x2 – 2xy + y2 – z2
(xii) x8 – y8
(xiii) 12x3 – 14x2 – 10x
(xiv) p2 – 10p + 21
(xv) 2x2 – x – 6
(xvi) 6x2 – 5xy – 6y2
(xvii) x2 + 2xy – 99y2
Answer:
(i) 10x2 – 18x3 + 14x4
HCF of 10, 18, 14 = 2
So, 10x2 – 18x3 + 14x4
= 2x2 (5 – 9x + 7x2)
(ii) 5x2y + 10xyz + 15xy2
HCF of 5, 10, 15 = 5
So, 5x2y + 10xyz + 15xy2
= 5xy (x + 2z + 3y)
(iii) p2x2 + c2x2 – ac2 – ap
= p2x2 – ap2 + c2x2 – ac2
= p2(x2 – a) + c2(x2 – a)
= (x2 – a) (p2 + c2)
(iv) 15(x + y)2 – 5x – 5y
= 15(x + y)2 – 5(x + y)
= 5(x + y) [3(x + y) – 1]
= 5(x + y) (3x + 3y – 1)
(v) (ax + by)2 + (ay – bx)2
On expanding, we have
= a2x2 + b2y2 + 2abxy + a2y2 + b2x2 – 2abxy
= a2x2 + a2y2 + b2x2 + b2y2
= a2(x2 + y2) + b2(x2 + y2)
= (x2 + y2) (a2 + b2)
(vi) ax + by + cx + bx + cy + ay
= ax + bx + cx + ay + by + cy [On grouping the like variables]
= x(a + b + c) + y(a + b + c)
= (a + b + c) (x + y)
(vii) 49x2 – 70xy + 25y2
= (7x)2 – 2 × 7x × 5y + (5y)2 [∵ (a – b)2 = a2 – 2ab + b2]
= (7x – 5y)2
(viii) 4a2 + 12ab + 9b2
= (2a)22 + 2 × 2a × 3b + (3b)2 [∵ (a + b)2 = a2 + 2ab + b2]
= (2a + 3b)2
(ix) 49p2 – 36q2
= (7p)2 – (6q)2
= (7p + 6q) (7p – 6q) [∵ a2 – b2 = (a + b) (a – b)]
(x) 100x3 – 25xy2
= 25x(x2 – y2) = 25x{(x)2 – (y)2}
= 25x(x + y) (x – y)
(xi) x2 – 2xy + y2 – z2
= (x – y)2 – (z)2 [∵ a2 -2ab + b2 = (a – b)2 and a2 – b2 = (a + b) (a – b)]
= (x – y + z)(x – y – z)
(xii) x8 – y8
= (x4)2 – (y4)2 [∵ a2 – b2 = (a + b)(a- b)]
= (x4 + y4) (x4 – y4)
= (x4 + y4) [(x2)2 – (y2)2]
= (x4 + y4) (x2 + y2) (x2 – y2)
= (x4 + y4 (x2 + y2) (x + y) (x – y)
(xiii) 12x3 – 14x2 – 10x
= 2x(6x2 – 7x – 5) [Now, as 6 × (-5) = -30 ⇒ -30 = -10 × 3 and -7 = -10 + 3]
= 2x(6x2 + 3x – 10x – 5)
= 2x{3x(2x + 1) – 5(2x + 1)}
= 2x(2x + 1) (3x – 5)
(xiv) p2 – 10p + 21
= p2 – 3p – 7p + 21 [Now, as 21 =-3 × (-7) and -10 = -3 – 7]
= p(p – 3) – 7(p – 3)
= (p – 3)(p – 7)
(xv) 2x2 – x – 6
= 2x2 – 4x + 3x – 6 [Now, as -6 × 2 = -12 ⇒ -12 = -4 × 3 and -1 = -4 + 3]
= 2x (x – 2) + 3(x – 2)
= (x – 2) (2x + 3)
(xvi) 6x2 – 5xy – 6y2
= 6x2 – 9xy + 4xy – 6y2 [Now, as 6 × (-6) = -36 ⇒ – 36 = -9 × 4 and – 5 = -9 + 4]
= 3x(2x – 3y) + 2y(2x – 3y)
= (2x – 3y) (3x + 2y)
(xvii) x2 + 2xy – 99y2
= x2 + 11xy – 9xy – 99y2 [Now, as -99 = -11 × 9 and -2 = -11 + 9 }
= x(x + 11y) – 9y(x + 11y)
= (x + 11y) (x – 9y)
Question 3. Divide as directed:
(i) 15(y + 3)(y2 – 16) ÷ 5(y2 – y – 12)
(ii) (3×3 – 6×2 – 24x) ÷ (x – 4) (x + 2)
(iii) (x4 – 81) ÷ (x3 + 3×2 + 9x + 27)
Answer:
(i) 15(y + 3)(y2 – 16) ÷ 5(y2 – y – 12)
y2 – 16 = (y)2 – (4)2
= (y + 4)(y – 4)
y2 – y – 12 = y2 – 4y + 3y – 12
= y(y – 4) + 3(y – 4)
= (y – 4)(y + 3)
Now,
= 3(y + 4)
(ii) (3x3 – 6x2 – 24x) ÷ (x – 4) (x + 2)
3x3 – 6x2 – 24x = 3x(x2 – 2x – 8)
= 3x{x2 – 4x + 2x – 8}
= 3x{x(x – 4) + 2(x – 4)}
= 3x(x – 4) (x + 2)
Now,
= 3x
(iii) (x4 – 81) ÷ (x3 + 3x2 + 9x + 27)
x4 – 81 = (x2)2 – (9)2 = (x2 + 9) (x2 – 9)
= (x2 + 9) [(x)2 – (3)2]
= (x2 + 9) (x + 3) (x – 3)
x3 + 3x2 + 9x + 27 = (x)2 + (x + 3) + 9 (x + 3)
= (x2 + 9) (x + 3)
= (x – 3)
— End of Factorisation Check Your Progress Class 8 ICSE Maths Solutions :–
Return to : – ML Aggarwal Maths Solutions for ICSE Class -8
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