8th grade Ch 3 L8

Solve each system of equations algebraically. 1. y = x + 7, y = 4. Solve for x and y.

• x = -3, y = 4

• x = 3, y = 4

• x = 4, y = 7

• x = -7, y = 4

Solve each system of equations algebraically. 2. y = x + 5, y = 3x. Solve for x and y.

• x = 2.5, y = 7.5

• x = 5, y = 10

• x = 1, y = 6

• x = 3, y = 8

Solve each system of equations algebraically. 3. y = x - 9, y = -4x. Solve for x and y.

• x = -1.8, y = -10.8

• x = 2, y = -8

• x = 1, y = -5

• x = -3, y = 3

Solve each system of equations algebraically. 4. x + 3y = 1, y = 2x + 5. Solve for x and y.

• x = -2, y = 1

• x = 1, y = 7

• x = 0, y = 5

• x = 2, y = 9

Seven people went to the movies. The number of adults was one more than the number of children. Write a system of equations that represents the number of adults and children. Solve the system algebraically. Interpret the solution.

• Let a = number of adults, c = number of children. a + c = 7, a = c + 1. Solution: a = 4, c = 3. There are 4 adults and 3 children.

• Let a = number of adults, c = number of children. a + c = 7, a = c - 1. Solution: a = 3, c = 4. There are 3 adults and 4 children.

• Let a = number of adults, c = number of children. a + c = 8, a = c + 1. Solution: a = 4.5, c = 3.5. There are 4.5 adults and 3.5 children.

• Let a = number of adults, c = number of children. a + c = 7, a = c + 2. Solution: a = 5, c = 2. There are 5 adults and 2 children.

A system of equations can be solved using which of the following methods?

• Graphing, substitution, and elimination

• Only by guessing the values

• By multiplying all equations together

• By ignoring one equation

Solve each system of equations algebraically. 1. y = x + 5 y = 6 Solve for x and y.

• x = 1, y = 6

• x = 6, y = 1

• x = 0, y = 5

• x = 5, y = 0

Solve each system of equations algebraically. 2. y = x + 12 y = -18 Solve for x and y.

• x = -30, y = -18

• x = 6, y = 18

• x = 18, y = 6

• x = -12, y = 0

Solve each system of equations algebraically. 3. y = x - 10 y = -12 Solve for x and y.

• x = -2, y = -12

• x = 2, y = -12

• x = -22, y = -12

• x = 2, y = 12

Solve each system of equations algebraically. 4. y = x + 15 y = 2x Solve for x and y.

• x = 15, y = 30

• x = 10, y = 25

• x = 5, y = 20

• x = 20, y = 35