Question

How do you solve `5x+12=x-4`?

Answer 1

`x=-4`

Explanation:

The trick to solving a simple equation as this one is, "isolation". Try to "isolate" the variable, x on one side and the numbers on the other side. Let's see how you can do this.
`5x + 12= x-4` Now why don't we subtract 12 on both sides
`5x + cancel(12) - cancel(color(red)(12))= x-4 - color(red)(12)`
What we have is now:
`5x = x-16` Well now let's bring `x` to the left side, we can do this by subtracting `x` on both sides:
`5x - color(blue)(x)= cancel(x)-16 - cancel(color(blue)(x)`
`4x = -16` we are not done we need to eliminate the `4`
Well let's divide both sides by 4:
`cancel(4)x * color(magenta)(1/cancel(4)) = -16*color(magenta)(1/4)`
And finally we have isolated `x`, so `x` is:
`x=-4`

Hope it helps. Follow this basic recipe an you will be able to solve any equation of this kind... Good Luck!