Help plz my teacher didn't explain how i'm supposed to solve these

See below for each answer. I did it step by step.

Step-by-step explanation:

90=(x+18)+x 90-18=x+x 90-18=2x 72=2x x=36

90=(x-52)+x 90+52=2x 142=2x x=71

180=(x-10)+(x-20)+x 180+10+20=3x. 190+20=3x 210=3x x=70

90=(x+36)+x 90-36=2x 54=2x x=26

90=(x+10)+(x+10) 90-10-10=2x 80-10=2x 70=2x x=35

180=(x+20)+x 180-20=2x 160=2x x=80

180=(x-14)+x 180+14=2x 194=2x x=97

180=(x+20)+(x+10) 180-20-10=2x 160-10=2x 150=2x x=75

828. all there is to it!

here, if you ever need with rounding (or other forms of arithmetic/math) again, use this:

thats the rounding one, but if you just click the top left, it shows you all the calculators you may need!

drop out of school or go to quizlet, quizlet is better

step-by-step explanation: