Question

if x-y=9and xy=2 find the value of xcube -ycube

Answer 1

${x}^{3 } - {y}^{3} = (x - y) ( {x}^{2} + y ^{2} - xy)$
put the values u will get the answer

Answer 2

your answer

apply

(x-y)3=x3-y3-3xy(x-y)

(9)3=x3-y3-3×2(9)

729=x3-y3-54

729+54=783=x3-y3