Question

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

`4a-color(white)("d")3b`

Explanation:

`2a+color(white)("d")b`
`ul(color(white)("d")a-9b larr" Add"`
`color(red)(3a-8b) larr" Sum of 2 sides"`

`color(white)("d")`

`7a-11b larr" Sum of all 3 sides"`
`ul(color(red)(3a-color(white)("d")8b)larr" Subtract")`
`4a-color(white)("d")3b larr" Remaining side"`