The order of operations is PEMDAS.
P stands for parentheses—you should always try to make whatever is inside the parentheses as simple as possible.
E is for exponent—raise numbers to exponents as soon as parentheses are as simple as possible
MD stands for multiplication and division. Do both of these in a left to right order, at the same time.
(Example: 4xx7+15-:3=28+15-:3=28+5=33)
AS stands for addition and subtraction, which are also both done from left to right simultaneously.
In your scenario, 4(9-6)^2, it may be tempting to try to do use the exponent. However, we can't do (9-6)^2 without first knowing what (9-6) is. This is why parentheses are always computed first.
We know that 9-6 is 3, so we can rewrite your original term as color(blue)(4(3)^2).
Now, which do we do next—multiply or square? In PEMDAS, exponent comes before multiplication, so we will square the 3 before we multiply by 4. Doing this in reverse is a very common mistake!
Once we square the 3, we get color(green)(4(9)). It is obvious that all there is to do now is multiply, leaving a final, simplified answer of color(red)(36).
