1. Do Now
3x – 6y = -3
2x + 4y = 30

2. Homework Solutions 1) x + y = -9 5x + 5y = -45

3. Homework Solutions 4) 2x + y = 3 -8x – 4y = -12

4. Homework Solutions 7) 5x + 3y = -10 15x + 9y = -30

5. Homework Solutions 10) 3x + 2y = -26 12x + 8y = -104

6. Substitution If x = 5, find the value of 3x.
The substitution property says that a quantity can be substituted for its equal in any expression.
We can use this property to solve systems of equations.

7. Solving Systems Using Substitution
Steps:
Find the equation that is solved for a variable.
(y = or x = )
Substitute into the OTHER equation.
Solve the new equation for the variable.
Substitute and solve for the other variable.

8. Solve using substitution.
y = 3x
x + 2y = – 21

9. Solve using substitution.
y = x – 4
3x + y = 8

11. x = 4y + 5
x – 3y = – 2

12. 4x + 5y = 11
y = 3x – 13

14. y = 4x – 1
y = 2x – 5

15. 3x + 2y = -9
x = y – 13

16. Permission Slips Due Wednesday!!
Homework
Worksheet pgs. 68 & 69 #’s 2, 8, 10
Permission Slips Due Wednesday!!