Question

X+Y=200
X-70=Y-40AGRADEÇO..


X+Y=21
2X+4Y-40

Answer 1

X=200-Y
SUBSTITUINDO O VALOR DEX
200-Y-70=Y-40
-Y-Y=-200+70-40
-2Y=-170
Y=-170/-2
Y=85

X=200-85
Y=115


X=21-Y
SUBSTITUINDO O VALOR DE X
2(21-Y)+4Y=-40
42-2Y+4Y=-40
2Y=-40+42
2Y=2
Y=2/2
Y=1

X=21-2
X=19