For this problem is it only asking for the exprssion(formula). Or do they want me to solve it.
(1) A triangle has sides 3x+7,4x-9,and 5x+6. Find the expression that represents its perimeter.
My answer:P=a+b+c
I think the question is asking for the expression, but I would take that to mean that you substitute the values for the sides; i.e.,
P = 3x+7+4x-9+5x+6=12x+4
P=12x+4 is the expression for the perimeter. That isn't solving it for no value is given for x.