Answer:
25 1/2.
Step-by-step explanation:
nth term = a1 + d(n - 1)
Here, a1 = -4 1/2
d = -1 1/2-(-3)
= -1 1/2 + 3
= 1 1/2
So,
21st term = -4 1/2 + 1 1/2(21 - 1)
= -4 1/2 + 1 1/2 * 20
= -4 1/2 + 30
= 25 1/2.
