Answer :
[tex]y=3x+13 \\
2x=y-9 \ \ \ |-y-2x \\ \\
y=3x+13 \\
\underline{-y=-2x-9} \ \ \ \hbox{add the sides} \\
y-y=3x-2x+13-9 \\
0=x+4 \\
x=-4 \\ \\
y=3x+13=3 \times (-4)+13=-12+13=1 \\ \\
\boxed{(x,y)=(-4,1)}[/tex]
y = 3x + 13
y = -2x + 9
2y = x + 22
2y = x + 22
2 2
y = 1/2x + 11
1/2x + 11 = 3x + 13
-1/2x -1/2x
11 = 2 1/2x + 13
-13 - 13
-2 = 2 1/2x
-2 = 2 1/2x
2 1/2 2 1/2
-0.8 = x
y = 3(-0.8) + 13
y = -0.24 + 13
y = 12.76
(x, y) = (-0.8, 12.76)
y = -2x + 9
2y = x + 22
2y = x + 22
2 2
y = 1/2x + 11
1/2x + 11 = 3x + 13
-1/2x -1/2x
11 = 2 1/2x + 13
-13 - 13
-2 = 2 1/2x
-2 = 2 1/2x
2 1/2 2 1/2
-0.8 = x
y = 3(-0.8) + 13
y = -0.24 + 13
y = 12.76
(x, y) = (-0.8, 12.76)