Question

the first two terms of the AP are -3 and 4.then it's 21 St term is ?​

Answer 1

First term = -3

Second term = 4

Common difference = 4 -(-3) = 7

n = 21

Using the formula,

$\boxed{a_{n} = a + (n-1)d}$

We get

= -3 + (21-1)7

= -3 + 20×7

= -3 + 140

= 137

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Answer 2

Answer:

137

Step-by-step explanation:

a=-3

and d=4-(-3)=7

so A21=a+20d

=-3+20*7

=-3+140

=-137