Question

Solve the system of linear equations by substitution. Check your solution.

1.
y = x + 2
y = 3x - 4

2.
y = 3x + 4
x + y = 8

3.
-2x + 3y = 9
y = 2x + 7

Answer 1

1. X+2=3x-4
6=2x
x= 3

2. y= 8-x
8-x = 3x+4
4= 4x
X= 1

3. -2x +3(2x+7)=9
-2x + 6x + 21 = 9
4x = -12
x= -3