Question

Me ajudem pff

A) x + y = 12
x - y = 0

B) x + y = 10
x + y2 = 15

C) x - y = 6
x + 2y =24

Answer 1

a) elimina o y e o -y (pq y + (-y) = 0)
então vc soma
x=12
x=0
____
2x=12
x=12÷2
x=6
6 + y = 12
y=12-6
y=6

b) x + y =10 × (-1)
x + y2=15
_____________
-x -y = -10
x + y2=15 (elimina x e -x)
____________________
y=5
x + 5 = 10
x=10-5
x=5

c) x - y=6 × (-1)
x+2y=24
____________
-x+y=-6
x+2y=24 (elimina o -x e o x)
______________________
3y=18
y=18÷3
y=6
x-6=6
x=6+6
x=12