Question

How do you solve y = 2x – 4 and 7x – 5y = 14?

Answer 1

Use substitution of the first equation into the second equation to ultimately get the unique solution `(x,y)=(2,0)`.

Explanation:

If you substitute `y=2x-4` into `7x-5y=14`, you'll get `7x-5(2x-4)=14`, which simplifies to `7x-10x+20=14` and then `3x=6` so that `x=2`.

Now plug `x=2` back into `y=2x-4` to get `y=2*2-4=0`.

The unique solution is therefore the point `(x,y)=(2,0)`.