Question

x+y=52, x-y=12
determinati x si y

Answer 1

x-y=12

x=12+y, subsituim in prima ecuatie

12+y+y=52

2y=52-12

y=40 : 2

y=20

x=12+20

x=32

Verificare

20+32=52

32-20=12

Answer 2

x=12+y
12+y+y=52
2y=52-12
2y=40
y=20

x+20=52
x=52-20=32