what is the first step to simplify 12-7+9

Answer 1

The first step is to subtract 7 from 12.

Here is the Order of Operations
Parentheses
Exponents
Multiplication and Division (from left to right)
and
Addition and Subtraction (from left to right)

You can as the acronym PEMDAS or as the mnemonic "Please Excuse My Dear Aunt Sally"

Hope this helps!