Question

se (x+y)² = 144 e x² + y² = 104, determine:
a) x + y
b) x. y
ME AJUDEM PFVR

Answer 1

a)
a)
a)
(x + y)² =144
x + y = $\sqrt{144}$
x+y = 12

b)
(x + y)² = x² + 2xy + y² 
144 = 104 + 2xy
2xy = 144-104
2xy= 40
xy = 20