Question

How do you solve `-3x + 9= 15`?

Answer 1

Work backwards doing addition and subtraction first and Division and multiplication next. x = -2

Explanation:

The order of operations is PEMDAS ( Parenthesis, Exponents, Multiplication Division Addition and Subtraction)

A way to remember this is to think.
If I get hurt in PE. I need to call an MD ASAP

remember a doctor an MD is one person so Multiplication and Division are done at the same time which ever comes first working from left to right.

remember ASAP is as soon as possible it is one time, so addition and subtraction are done at the same time which ever comes first working from left to right.

The order of operations backwards is PE SADM

A way to remember is to think
If I lose something in PE I am a SAD (Man or Mam)

So first subtract 9 from both sides This gives

`-3x + 9 -9 = 15-9` This gives

`-3x = 6`

Now Divide both sides by -3 This gives

`(-3x)/(-3) = 6/(-3)` Dividing gives

x = -2