How would I answer this on my math test?? I’m not exactly looking for answers, but I need an explanation on how to do these types of problems so I can know for when I take my math test PLEASE SOMEBODY HELPPP (I’m in 8th grade and I need a simple-ish explanation plssss)

How would I answer this on my math test Im not exactly looking for answers but I need an explanation on how to do these types of problems so I can know for when class=