Question

How do you solve the system of equations `-\frac { 3} { 4} x + y = - 1` and `- 3x + \frac { 1} { 2} y = 10`?

Answer 1

`x=-4`, and `y=-1 3/16`

Explanation:

I'm going to use a method called substitution. First, add `3/4x` to both sides of the first equation. This leaves you with `y=3/4x-1`. Substitute this value of `y` into the second equation to get `-3x+1/2(3/4x-1)=10`. Simplify this equation to get `-3x+3/8x-1/2=10`. Combine like terms and simplify to get `-21/8x=21/2`. Divide on both sides by `-21` to get `1/8x=-1/2`. Multiply by 8 on both sides to get `x=-4`. Substitute this value of `x` into our equation of `y=3/4x-1` to get `y=-3/16-1=-1 3/16`.