Question

Simplify
(5x + 7y)³
with this formula (a+b)³=a³+3a²b+3ab²+b³​

Answer 1

Answer:

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Maharashtra Board Class 8 Maths Solutions Chapter 5 Expansion Formulae Practice Set 5.3

August 13, 2019 by Laxmi

Maharashtra State Board Class 8 Maths Solutions Chapter 5 Expansion Formulae Practice Set 5.3

Question 1.

Expand:

i. (2m – 5)³

ii. (4 – p)³

iii. (7x – 9y)³

iv. (58)³

v. (198)³

vi. (2p−12p)3

vii. (1−1a)3

viii. (x3−3x)3

Solution:

i. Here, a = 2m and b = 5

(2m – 5)³

= (2m)³ – 3(2m)² (5) + 3(2m) (5)² – (5)³

… [(a – b)³ = a³ – 3a²b + 3ab² – b³]

= 8m³ – 3(4m²)(5) + 3(2m)(25) – 125

= 8m³ – 60m² + 150m – 125