Question

Sabendo que x² + y² = 26 e que xy = 5 determine o valor de:

a) (x + y)²

b) (x - y)²

favor, tentar me explicar .

Answer 1

a)(x²+2xy+y²)= x²+y²+2xy=
26+2.5= 26+10= 36

b)(x²-2xy+y²)= x²+y²-2xy=
26-2.5= 26-10= 16