SSC (English Medium) Class 8Maharashtra State Board
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# Simplify (4a − 3)3 − (4a +3)3 - SSC (English Medium) Class 8 - Mathematics

ConceptExpansion of (A + B + C)2

#### Question

Simplify

(4a − 3)− (4a +3)3

#### Solution

It is known that,

$\left( a + b \right)^3 = a^3 + b^3 + 3 a^2 b + 3a b^2 ; \left( a - b \right)^3 = a^3 - b^3 - 3 a^2 b + 3a b^2$

$\ \left( 4a - 3 \right)^3 - \left( 4a + 3 \right)^3$

$= \left( 4a \right)^3 - \left( 3 \right)^3 - 3 \times \left( 49 \right)^2 \times 3 + 3 \times 49 \times \left( 3 \right)^2 - \left\{ \left( 49 \right)^3 + \left( 3 \right)^3 + 3 \times \left( 49 \right)^2 \times 3 + 3 \times 49 \times \left( 3 \right)^2 \right\}$

$= 64 a^3 - 27 - 144 a^2 + 108 - 64 a^3 - 27 - 144 a^2 - 108$

$= - 54 - 288 a^2$

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#### APPEARS IN

Balbharati Solution for Balbharati Class 8 Mathematics (2019 to Current)
Chapter 5: Expansion formulae
Practice Set 5.3 | Q: 2.3 | Page no. 27
Solution Simplify (4a − 3)3 − (4a +3)3 Concept: Expansion of (A + B + C)2.
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