Question

X-3y=9
2x+3y=6

X=3y
2x-4y=6

Answer 1

1)

x-3y = 9
2x+3y = 6

3y = 6-2x

x-6+2x= 9
3x = 15
x = 15/3 -> x = 5

2.5+3y=6
10+3y=6
3y = -4
y = -4/3

Corrigindo:

5-3.-4/3 = 9
4-3.-1,333... = 9
5+4=9
9 = 9

2.5+3.-4/3 = 6
10+3.-1,3333... = 6
10-4 = 6
6 = 6

2)

x = 3y
2x-4y = 6

2.(3y)-4y = 6
6y-4y = 6
2y = 6
y = 6/2 -> y = 3

x = 3.3
x = 9

Corrigindo:

9 = 3.3
9 = 9

2.9-4.3 = 6
18-12 = 6
6 = 6