So perimeter is adding all sides
In this picture, you have all sides, so add them up!
(2a-3)+(3a+1)+(2a) = P
So this expression shows that we're adding all sides that gives us the P, or perimeter :)
Answer:
x=26
Step-by-step explanation:
3x +12 =90
subtract 12 from each side
3x=78
divide 3 from each side
x=26