Question

if x-y=5 and xy=84 find the value of x cube - y cube​

Answer 1

Answer:

Hii Ridhi,

Here, x-y=5 => (x-y)^2 =25

=> x^2+y^2-2xy=25

=> x^2+y^2+xy = 25+3xy

=> x^2+y^2+xy= 25 +3×84 = 277

Hence, x^3-y^3 = (x-y)(x^2+y^2+xy)= 5×277 = 1385 ans..

Thank you! !