Answer: 20
20 since you have to divide 100 by 5 which equals 20 since you have to use the inverse operation of multiplication which is division.
Hope this helps!
Answer:
no I don't think it's not beach or not the same
3x+21-12=8x-28
collect the like terms
3x-8x=-28(21-12=9)
-5x=-28-9
-5x=-37
x=7.4
