ok to simplify this question you have to work with the pemdas(parenthesis, exponents, multiplication, division, addition, and subtraction) we have to set x by itself so to do this lets first subtract 10 from both sides (because 10 is a positive and the only way to get ride of a positive is with a negative) this will give result you in 3x=36, now divide to leave x completly by itself when you divide you should get x=12 (why 12, well because 3 fits in 36 12 times, to check this out you can multiply 3 times 13 and see what you get!! you will get 36 so we know that answer is correct) so you answer would be "x=12"
Hope this helps