Question

Consider the following pair of equations:

y = −2x + 8
y = x − 1

Explain how you will solve the pair of equations by substitution. Show all the steps and write the solution in (x, y) form.

Answer 1

Answer:

(3,2)

Step-by-step explanation:

y = -2x + 8

y = x-1

Substitute x-1 for y in the equation y = -2x + 8.  x-1 = -2x + 8

Use the Additive Property to move the

constant terms to one side of the equation.      x-1 = -2x + 8

                                                                                +1           +1

                                                                                  x = -2x + 9

Now do the same to the variable terms.              +2x +2x

                                                                                 3x = 9

Divide both sides of the equation by the

constant in the variable term.                               ÷3 = ÷3

                                                                                   x = 3

To find y, simply substitute the value of x into

one of the original equations.                                 y = x-1

                                                                                   y = 3-1

Solve:                                                                         y = 2

The solution is (3, 2).