Question

What are x and y if `x+y=4` and `y=-7x+4`?

Answer 1

Please look below.

Explanation:

`x + y = 4` ---(1)

`y = -7x + 4` ---(2)

The `x` s and `y` s in the question are of the same value. This means that you can substitute the value of `y` in the second equation into the first equation:

`x + (-7x +4) = 4`

This allows you to find `x`:

`x-7x + 4 = 4`

`-6x = 0`

`x = 0`

Then this value can be substituted into either of the given equations:

`0 + y = 4`

`y = 4`

So `x = 0` and `y = 4`.