Question

How do you solve `-4 = -1+x`?

Answer 1

This is an equation and the idea is to find the value of `x` that makes the right side equal (equation) to the left one. To do that try to ISOLATE `x` on one side and send the numbers to the other side of the `=` sign. Remember that every time a term "crosses" the `=` sign it changes sign!
So: take `-1` and send it to the left (changing sign):
`-4+1=x`
evaluate `-4+1`
`-3=x`
So, finally, you got that the value of `x` that satisfies your equation is `-3`!
If you substitute `-3` in your equation in place of `x`, you'll get:
`-4=-1color(red)(-3)` which is true.