(d) \( \mathrm{T}_{n}=9 n=4 \) is the \( n^{\text {bi }} \) term of a linear number sequence. (1) Determine the first four terms of the sequence. (2) Which term is equal to 986?

To find the first four terms of the linear sequence defined by \( \mathrm{T}_{n} = 9n - 4 \), we can substitute \( n \) with the first four positive integers: 1. For \( n=1: \mathrm{T}_{1} = 9(1) - 4 = 5 \) 2. For \( n=2: \mathrm{T}_{2} = 9(2) - 4 = 14 \) 3. For \( n=3: \mathrm{T}_{3} = 9(3) - 4 = 23 \) 4. For \( n=4: \mathrm{T}_{4} = 9(4) - 4 = 32 \) Thus, the first four terms of the sequence are: \( 5, 14, 23, 32 \). To find which term is equal to 986, we set the general formula equal to 986: \[ 9n - 4 = 986 \] Solving for \( n \): \[ 9n = 990 \] \[ n = \frac{990}{9} = 110 \] Therefore, the term that is equal to 986 is the 110th term.