Question

for option b why does doing 34=3n-1 give u the answer instead of 3(34)-1=tn on question 8

Answer 1

Answer:

Correct option are:

A and C

Explanation:

Question 8

To know which of the options contain 34, we test each of them

$t_n=6+(n-1)4$

For n = 8

$\begin{gathered} t_8=6+(8-1)(4) \\ =6+28 \\ =34 \end{gathered}$

Also

$\begin{gathered} t_1=12,d=5.5,t_n=34 \\ \\ t_n=12+(n-1)5.5 \\ \\ 34=12+(n-1)5.5 \\ 34-12=(n-1)5.5 \\ n-1=\frac{22}{5.5} \\ \\ n=4+1=5 \end{gathered}$

A and C are the correct options