How can I solve this system of linear equations by substitution 2x-3y=-24 and x+6y=18

Mathematics · Middle School · Wed Jan 13 2021

Answered on

Given the system of linear equation:

2x -3y = -24

x + 6y = 18

Solve by substitution.

In order to solve by substitution, we must equate first the two equations into one solution,

2x - 3y + 25 = x + 6y - 18

Transpose x + 6y - 18 on the other side of the equation. Hence, we must take note that when transposing a number, the sign changes.

2x - 3y + 25 - x - 6y + 18 = 0

x - 9y + 43 = 0

We solve first  for the value of y.

x + 43 = 9y

y = 1/9 x + 43/9

Solve for x.

x = 9y -43

Final answer:

y = 1/9 x + 43/9

x = 9y -43