Question

Solve the system by substitution -4x+3y=-2 y=x-1

Answer 1

Substitute y=x-1 for y in the first equation to get -4x+3(x-1)=-2

-4x+3x-3=-2

-x-3=-2

-x=1

x=-1

Explanation:

Answer 2

x = -1

y = -2

Explanation:

If you look at the second equation, y is already isolated for us:

y = x - 1

so all we need to do is plug in the value for y into the first equation:

-4x + 3(x - 1) = -2

Next all we do is algebra:

[distribute] -4x + 3x - 3 = -2

[condense] -1x - 3 = -2

[add] -1x = 1

[divide] x = -1

Now that we have the value of x, we can use it to find y by plugging it in to either equation.

y = x - 1

[plug in] y = -1 - 1

[condense] y = -2

Answers: x = -1, y = -2