Question

x-y=3
3x+3y=16
só preciso da formula

Answer 1

x= 3+y
3x+3y = 16
3(3+y)+3y=16
9+3y+3y=16
3y+3y=16-9
6y = 7
y = 7/6

x = 3 + 7/6
x = 18+7/6
x = 25/6

S = (25/6 , 7/6)