Question 5

Solve the following system of equations by using the substitution method.

y = 6x - 11

-2x - 3y = - 7

(1, 2)

(2, 1)

(-3, 1)

(2, 4)

answer is (2,1)

y = 6x - 11

-2x - 3y = - 7

Substitute 6x - 11 for y in the second equation

-2x - 3 (6x-11) = - 7

-2x - 18x + 33 = - 7

-20x + 33 = - 7

Now subtract 33 on both sides

-20x = - 7 - 33

-20x = - 40 (divide by - 20 on both sides)

x = 2

We know y = 6x - 11

Plug in 2 for x and find out y

y = 6 (2) - 11 = 12 - 11 = 1

So answer is (2,1)