Question

Quanto da x+y=200 e x-70=y-40

Answer 1

x + y = 200

x - y = 30( 70 -40)

2x = 230

x = 230/2

x = 115

x + y = 200

115 + y = 200

y = 200 - 115

y = 85

S = { 115, 85}