The answer is 8
Order of operations:(Please Excuse My Dear Aunt Sally)
Parentheses
Exponents
Multiplication
Division
Add
Subtract
When it comes down to multiplication and division you do whichever comes first , left to right same with add and subtract so..
Step1: 2 squared = 4
Step2: 4/4=1
Step3: 1x10=10
18-10=8 . Final answer is 8