What is one clue that lets you know that a math problem requires you to do a 2 steps/ multi-step?

The main clue is that one step alone doesn't get you to the answer.

Problem solving is an art.  The best book to learn about math problem solving is the classic How To Solve It by G. Polya.  

Here's a pdf I found online:

https://math.hawaii.edu/home/pdf/putnam/PolyaHowToSolveIt.pdf

x=17

step-by-step explanation:

solve 3x-24=x+10

then that makes it 2x=34 because you subtract an x from both sides to get rid of the one on the right, and then you add 24 to both sides to get rid of the 24 on the left

divide by both sides by 2 to get your answer so that you can get your answer