Question

Find the 20th term of the A.P 12, 7, 2​

Answer 1

Step-by-step explanation:

d = a2 - a12

d = 7 -12

d = - 5

a20 = a + (n -1 ) d

a20 = 12 + (20 -1) - 12

a20 = 12 + 19 × -12

a20 = 12 - 228

a20 = -216

I hope it helps you

Answer 2

Answer:

$-216$

Step-by-step explanation:

The given AP is 12,7,2

⇒$a(first$ $term)$ $=12$

⇒$d(common$ $difference)$$=a_{1} -a_{2}$ $= -5$

⇒$n=20$

We know that $a_{n}$(nth term of an AP) $= a+(n-1)d$

⇒$a_{20} =$ $12+(19)(-12)$

⇒$a_{20} =$ $12-228$

⇒$a_{20} =$ $-216$