An equilateral triangle has a premimeter of 3x + 30. what is the length of each side of the triangle?

3x + 30 divided by each of the 3 sides would equal x+10.

Because 3(x+10) = 3x+10

Since an equilateral triangle has three equal sides you need to divide the perimeter by 3 to get 3 equal lengths.

First - set it up as division and get:
(3x+30)/3

Second - to divide by three you need to factor out 3x+30 and you will get:
3(x+10)/3

Third - you have to divide the two 3'sand get:
1(x+10)/1 = x+10

ANSWER:
X+10

And if you wanted to check you could add x+10+x+10+x+10
Combine like terms and you'll get back to the perimeter of 3x+30