Question

if 5x - 4x =7 and xy = 8 , find : 125 x power 3 - 64y power 3​

Answer 1

Answer:

(5x-4y) =7

(5x-4y) ³=7³

125x³-64y³-3*5x*4y*(5x-4y) = 343

125x³-64y³-60*8*7= 343

125x³-64y³= 3703

Answer 2

$\fbox{Correct Question}$

If 5x - 4y =7 and xy = 8 , find : 125 x³ - 64y³

$\fbox{Answer}$

$\sf (5x - 4y) = 7$

$\sf (5x - 4y) ^ 3 = 7 ^ 3$

$\sf 125x³-64y³-3*5x*4y*(5x-4y) = 343$

$\sf 125x³-64y³-60*8*7= 343$

$\sf 125x ^ 3 - 64y ^ 3 = 3703$

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