1. Solving Systems of Equation by Substitution

2. Objective
To be able to solve a system of equations by substitution.

4. Substitution Since x = 2 We can now substitute it back in.
y = 3x (the 1st equation)
y = 3(2) -1(put in the x value)
y = (solve for y)
y = (2,5) is the solution

6. Substitution y + 1 = x (the 2nd equation)
Since y = 1 Now substitute
y + 1 = x (the 2nd equation)
1 + 1 = x (put in the y value)
2 = x (solve for x)
(2,1) is the solution

7. Solving for x or y
First solve for x or y

8. 3(-2y + 4) + 5y = 14
-6y y = 14
-y + 12 = 14
-y = 2 y = -2

10. Solving Systems of Equation by Substitution