the perimeter of a triangle is 12b+5. Two sides have the following length:4b and 3b+15. What is the length of the third side?

Answer:The length of the third side 2.5.

Step-by-step explanation:

We already know the length of two side but we don't know the length of one side so we will represent it by b and we know they three lengths add up to 12b+5.

4b + 3b+15 + b = 12b + 5

Solve for b.

8b + 15=12b + 5

-8b - 8b

15+4b + 5

-5 - 5

4b/4=10/4

B=2.5

So the length of the third side is 2.5

4 (2.5) + 3 (2.5) + 15+2.5=12 (2.5) + 5

35=35