Question

WILL MARK BRAINLIST!!!!!!!!!!!!

Answer 1

Answer:

$T_{21} = 53$

Step-by-step explanation:

Given

$a = -7$

$d = 3$

Required

Determine $T_{21}$

This is calculated using sum of Ap formula

$T_n = a + (n - 1)d$

In this case:

$n =21$

So, the equation becomes

$T_{21} = -7 + (21 - 1) * 3$

$T_{21} = -7 + 20 * 3$

$T_{21} = -7 + 60$

$T_{21} = 53$