"Perimeter" is the distance all the way around the drawing. If the drawing has sides, then the perimeter is the SUM of the lengths of all the sides. It's exactly the distance an ant would have to walk along the line, to get all the way around to where he started from.
To get the perimeter of the triangle, you have to add up the lengths of the three sides.
(2a - 3) + (2a) + (3a + 1) =
2a - 3 + 2a + 3a + 1 .
Add up all the 'a's: 2a + 2a + 3a = 7a
Add up all the just plain numbers: -3 + 1 = -2
Write them together, as a binomial: 7a - 2
THAT's your expression for the perimeter.
Well you would have to round this 5 and above goes up. Since 1 is lower than 5 that would leave you at 6.37. 7 rounds up so that would change to 6.4. Lastly 4 would round down, So that would leave you with 6. Now 6 is the simplest form but if your looking for rounded to the nearest tenth the answer would be 6.4. If your looking for rounded to the nearest 100th place 6.37. But over all simplest form is 6.
Answer:
substitute that (6) in X so f(6) = 2(6) which is = 12