Question

***WILL MEDAL***
The perimeter of a triangle is 7a - 11b. If two of its sides are 2a + b and a - 9b, what is the third side?

Answer 1

To find the perimeter you add up all the sides of the triangle

Answer 2

we'll us x to represent the missing side

Answer 3

(2a+b) + (a-9b) + x = 7a-11b

Answer 4

now just simplify the equation and solve for x

Answer 5

Do you know how to do that?

Answer 6

first add all the like terms on the left side

Answer 7

3a - 8b + x = 7a-11b

Answer 8

now move the a and b terms to the right side of the equation to get x by itself

Answer 9

x = 4a - 3b

Answer 10

This means that the missing side is 4a - 3b

Answer 11

Ohhhhh that makes since .