1. Solving Systems Check Point Quiz Corrections

2. x y -3 3 x y 1
1/3
Solve each system of equations by graphing. 1. y = 2x – 4 2. x – y = 3 y = -x + 5 3x + y = 1

3. Convert the equations from standard form to slope-intercept. 3
Convert the equations from standard form to slope-intercept. 3. 6x + y = 5 -6x -6x  Subtract 6x from both sides y = -6x x + 2y = 8 -5x -5x  Subtract 5x from both sides 2y = -5x + 8  Divide both sides by y = -5/2x + 4

4. Solve the system of equations by substitution. 5
Solve the system of equations by substitution. 5. y = 2x – 9 3x + 2y = -4
3x + 2y = -4  Rewrite the 2nd equation
3x + 2(2x – 9) = -4  Substitute 2x – 9 for y
3x + 4x – 18 = -4  Distribute
7x – 18 = -4  Combine like terms
7x = 14  Add 18 to both sides
x = 2  Divide both sides by 7
Solution:
(2, -5)
y = 2x – 9  Rewrite the 1st equation
y = 2(2) – 9  Substitute 2 for x
y = 4 – 9  Multiply
y = -5  Subtract