Question

x-y=4, xy=45 find the value of x³-y³​

Answer 1

Answer:

x-y=4

=> (x-y)^2=4^2

=> x^2+y^2-2xy=16

=> x^2+y^2=16+2xy=16+2.45=16+90=106

x^3-y^3

=(x-y)(x^2+xy+y^2)

=4(x^2+y^2+xy)

=4(106+45)

=4.151

=604

Answer 2

If x-y= 4 , x*y= 45 ,
Then x = 9 and y=5
x*x*x-y*y*y = 9*9*9-5*5*5
729-125
= 604