Question

if x+y=1 and x-y=7 , then the value of 5(x3+y2) is equal to​

Answer 1

Answer:

x-y = 7 …(1)

xy=9 …(2)

Square (1) to get

x^2–2xy+y^2 = 49, or

x^2+y^2 = 49+2xy = 49 +(2*9) = 49+18 = 67. Answer