Question

simplify
$( { \frac{x}{3} + \frac{y}{5}) }^{3} - ( { \frac{x}{3} - \frac{y}{5} ) }^{3}$

Answer 1

here's your answer

we know that - (a³-b³) = a-b(a²+b²+ab)

so, {x/3+y/5-(x/3-y/5)}{(x/3+y/5)²+(x/3-y/5)²+(x/3+y/5)(x/3-y/3)
= 2y/5(x²+y²+2xy/15+x²+y²-2xy/15+x²/9-y²/25)
= 2y/5(x²/3+y²/25) ANS..

⚡hope it helps you ⚡
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