Question

if X square + Y square = 49 and x - y = 23 then find the value of x cube - y cube
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Answer 1

Answer:

x-y = 23

Squaring both sides,

x² + y² - 2xy = 529

also, x² + y² = 49

So, -2xy=480

xy= -240

Now, x-y=23

Cubing Both sides,

x³ - y³ -3 (xy)(x-y) = 12167

x³ - y³ -3(-240)(23) =12167

x³ - y³ + 16560 = 12167

x³ - y³ = -4393