Question

(5x-7y)³ + (5x+7y)³ pls give me answer with method ​

Answer 1

Step-by-step explanation:

(5x-7y)³+(5x+7y)³

Let (5x-7y) be a and (5x+7y) be b

a³+b³= (a + b)(a²- ab + b²)

therefore

(5x-7y)³+(5x+7y)³=(5x-7y+5x+7y)

{(5x-7y)²-(5x-7y)(5x+7y)+(5x+7y)²}

=10x{(25x²+49y²-70xy)-(25x²-49y²)+(25x²+49y²+70xy)}

=10x(25x²+49y²-70xy-25x²+49y²+25x²+49y²+70xy)

=10x(25x²+147y²)

=250x³+1470xy²

hope it helps you

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