Question

If x + y =12,and xy =15, then the value of x3+ y3 is

Answer 1

Answer:

1188

Step-by-step explanation:

(x+y)3 = x3 + 3x2y + 3xy2 + y3

(12)3 = x3 + y3 + 3 x 15x + 3 x 15y

1728-45x-45y= x3 + y3

x3 + y3 = 1728-45(x + y)

x3 + y3 = 1728 - 45 x 12

            = 1188