Solving Systems of Linear Equations by Substitution

What is the first step in solving a system of linear equations by substitution?

• Graph the equations.

• Multiply both equations by a constant.

• Add the two equations together.

• Solve one of the equations for one of the variables.

In Example 1, what is the value of x after solving the equation 6x + 10x + 45 = -19?

• -4

• 16

• 4

• -16

After finding x = -4 in Example 1, which equation is used to find the value of y?

• 3x + y = -1

• 6x - 5y = -19

• y = x + 3

• y = -2x - 9

In Example 2, what is the isolated variable after manipulating the equation -x + y = 3?

• y

• x

• 3

• -x

What is the value of y in Example 2 after solving the equation y = x + 3 with x = -1?

• 1

• 2

• 3

• 4

What is the final ordered pair solution for the system in Example 2?

• (-2, 1)

• (1, -2)

• (-1, 2)

• (2, -1)

In Example 3, what is the equation that represents the relationship between the adult and student ticket prices?

• x = 2y

• 64x + 132y = 1040

• x + y = 1040

• 2x = y

How many adult tickets were sold in Example 3?

• 2

• 1040

• 64

• 132

What is the price of a student ticket in Example 3?

• $8

• $6

• $4

• $2

What is the total revenue from student tickets in Example 3?

• $528

• $264

• $1040

• $132