Like terms are terms that have something in common like an exponent or variable
8. 3a & 16a
9.

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10.

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11.

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Try 12 & 13 on your own to see if you get the hang of it - if you want me to check it ; put your answer in the comment section of my answer :))) I believe in you .
A. 2.4971.1 in because that is the biggest number compared to all of the others which will make it the tallest and closest to the surface of the yoga ball.