GEOMETRY please help I’m struggling vv badly

Bring the fraction a/a-4 to a denominator of 16-a^2

The first side of a triangle measures 5 in less than the second side, the third side is 3 in more than the first side, and the perimeter is 17 in. how long is the third side? if s represents the length of the second side, which of the following represents the length of the third side? s-5 ws-2 s+ 3 next question ask for turn it in

Someone me i need with this stuff