When solving problems, which of these is performed before the others? a. multiplication b. addition c. exponents d. subtraction

From that list, the exponents should be handled first.

Here's the memory device for the order of operations
that I often see here on .  I didn't learn it this way,
but this is a good and handy thing to remember:
 
               P  E  M  D  A  S

It stands for the order in which operations should be performed
if you're working to simplify an expression that has several different
operations in it.

Parentheses
Exponents
Multiplication
Division
Addition
Subtraction

The rocks expand when there hot/warm  and contract when they are cold.

As newton's first law states a object in motion stays in motion