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

(3,2)

Explanation:

y = −2x + 8

y = x − 1

Substitute the second equation into the first equation for y

y = -2x+8

x-1 = -2x+8

Add 2x to each side

x-1+2x = -2x+8+2x

3x -1 = 8

Add 1 to each side

3x-1+1 = 8+1

3x =9

Divide by 3

3x/3 = 9/3

x=3

Now find y

y = x-1

y =3-1

y=2

(3,2)