Terms whose variables (such as x or y) with any exponents (such as the 2 in x2) are the same. Examples: 7x and 2x are like terms because they are both "x".
Answer (for question 1): For step one, you would just have to expand the brackets. The number of times multiplication would be used is 3 times. If you are confused, I attached a diagram in my ‘side notes’ section.
Answer (for question 2): -5x squared and -12x squared are like terms because they both end in x squared.
Answer (for question 3): There are no more like-terms.
