Question

Ache o valor de x e y no sistema:
3.(x-y)=6
x/3 + y/5 = 2/3

Answer 1

x/3+y/5=2/3
x/3=2/3-y/5
x/3=(10-3y)/15
15x=30-9y
x=(30-9y)/15

3x-3y=6
3((30-9y)/15)-3y=6
((90-27y)/15)-3y=6
90-27y-45y=6
90-72y=6
-72y=6-90
-72y=-84
y=-84/-72
y=7/6


3x-3y=6
3x-3(7/6)=6
3x-21/6=6
3x=6+21/6
3x=57/6
x=57/6*1/3
x=57/18