Question

X = 3y - 6 2x - 4y = 8 Solve the system of equations using substitution.

Answer 1

x = 3y - 6 so:
2(3y - 6) - 4y = 8
6y - 12 - 4y = 8
2y - 12 = 8
2y = 20
y = 10

x = 3(10) - 6
x = 30 - 6
x = 24

Answer 2

Equation 1) x = 3y - 6
Equation 2) 2x - 4y - 8

Basically, for equation 1, you would move the 3y to the other side so that x and y are on the same side. However, because it is a positive, when moving it over, it becomes a negative.

1) x - 3y = -6
2) 2x - 4y = 8

Multiply ALL of equation 1 by 2 so that you could find the value of y.

1) 2(x - 3y = -6)

1) 2x - 6y = -12
2) 2x - 4y = 8

Subtract equations :)

-2y = -20

Divide both sides of the equation by -2, so that y is isolated.

y = -20/-2

y = 10

Plug in 10 for y in the first equation :)

x = 3y - 6

x = 3(10) - 6

Simplify.

x = 30 - 6

Simplify.

x = 24

So, x = 24, and y = 10

~Hope I helped!~