Chapter 5 Review

Solve each system of equations by elimination.
-a + 5b = 12
3b - 10 = -a

• a = 7/4  b = 11/4
• a = 3  b = 3
• a = 1/2  b = 1/3
• a= -3  b = -3

Solve this system by elimination.
x + y = 18
2y + x = 20

• x = 2  y = 16
• x = 5.8  y = 12.2
• x = 16  y = 2
• x = 12.2  y = 5.8

Solve each system by substitution method.
y + 3x = -2
-5y - 10x = 0

• x = 2  y = 4
• x = 4  y = 2
• x = -4   y = -2
• x = -2   y =4

Solve each system by substitution method.
1/2y + 2x = 3
3y = 4x + 10

• x = 2  y = 1/4
• x = 1/4  y = 2
• x = 1/2  y = 4
• x = 4  y = 1/2

How many solutions does this system have?
1/2x + 1/3y = 1
3x + 2y = 12

• infinite/many
• one and only one
• none
• what is this asking?

Grab graph paper and solve by graphing.
y = -0.5x +2
2y = x + 4

• (-2, 0)  x = -2, y = 0
• (2,0) x = 2, y = 0
• (0,2)  x = 0 , y = 2
• (0, -2) x = 0, y = -2

Grab a piece of graph paper to solve.
1/2y = -x + 4
y = 2x + 2

• (1.5, 5)  x = 1.5, y = 5
• ( 5, 1.5)  x = 5, y = 1.5
• ( -1.5, 5) x = -1.5, y = 5
• (-5, -1.5) x = -5, y = -1.5

How many solutions does this system have?
-4x = y + 2
3y = x + 7

• infinite/ many
• one and only one
• none
• what is this asking?