Solve system of equation by substitutionx-2y=3, 4x-8y=12

Mathematics · Middle School · Tue Nov 03 2020

Answered on

Given:

x -2y =3

4x - 8y = 12

Solve the systems of equation:

Solution:

In order to solve the systems of equation, we can rewrite each equation as,

x -2y =3

x - 2y -3 = 0

4x - 8y = 12

4x - 8y - 12 = 0

Equate the two equations in one single solution:

x - 2y -3 = 4x - 8y - 12

Solve for x and y, separately. We can start first by transposing all the values on one side, hence we must take note that in transposing a number, the sign changes.

4x - 8y - 12 + x + 2y  + 3 = 0

3x + 6y - 9

Factor out 3 in the equation.

3(x + 2y -3) = 0

Solve for x.

x = 2y + 3

Solve for y.

2y = 3 + x

y = 3/2 + ½x

Final answer:

x = 2y + 3

y = 3/2 + ½x