Substitute Variables

m=8, n=6, p=4, q=2
Evaluate each expression below(substitute the variables)

If x = 1, y = 3, and z = 2, what is the value of the expression 4xy + 3xz+ 7y?

• 46 

• 42

• 39

• 23

Solve the system by using the substitution method

• (3,6)

• (6,3)

• (1,4)

• (4,1)

Solve the system of equations using the substitution method

• (-2,6)

• (6,-2)

• (-2,4)

• (4,-2)

What is the first step to solve a system with substitution?

• Substitute the values found from the previous step into one of the original equations and solve for the remaining variable

• Solve the linear system for both its variables

• Solve one equation for one of its variables

• Substitute the expression from the previous step in the other two equations to obtain a linear system in two variables

What is the final step to solve a system with substitution?

• Substitute the values found from the previous step into one of the original equations and solve for the remaining variable

• Solve the linear system for both its variables

• Solve one equation for one of its variables

• Solve one equation for one of its variables

Solve for x and y using the substitution method.

5x + 3y = 7

y = 4

• (4,1)

• (4,-1)

• (1,4)

• (-1,4)

Solve the following systems of equations using substitution:

2y + x = -15

x = 3y

• (-3,-9)

• (-9,-3)

• (-3,9)

• (9,-3)

Solve this system by substitution.

• (1,-4)

• (1,4)

• (-4,-7)

• (-7,-4)