To find the value of an expression with one or more operations?

use PEMDAS this is called the order of operations and is an acronym. here is what is stands for

P=Parenthesis

E=Exponents

M=Multiplication

D=Division

A=Addition

S=Subtraction

You have to do whatever is in the parenthesis first then go onto the exponents... then go to the next operation until all things are simplified. Then you can isolate you variable and find the value of it in the expression.