You are told to choose the choices equal to T(8). T(8) means that you need to find the possible ways to write the y-value when n = 8, since 8 is being substituted in for "n."
1) First, plug in n = 8 into the equation you're given, <span>T(n) = 4n - 5: T(8) = 4(8) - 5 T(8) = 32 - 5 T(8) = 27
That is answer choice C, making choice C correct. You can eliminate choice B, since 27 </span>≠ 37.
2) Check answer choice A. Is T(5) + T(3) = 27? T(5) means you need to plug in 5 for n. T(3) means you need to plug in 3 for n. T(5) + T(3) = [4(5) - 5] + [4(3) - 5] = [20-5] + [12-5] = 15 + 7 = 22
Since 22 ≠ 27, you can eliminate choice A.
3) Check answer choice D. Is T(7) + 4 = 27? T(7) means you need to plug in 7 for n. T(7) + 4 = [<span>4(7) - 5] + 4 </span>= [28 - 5] + 4 = 23 + 4 = 27
