Question

The 10 term of an AP is -4 and its 22 term is -16. find it's 38 term​

Answer 1

Step-by-step explanation:

A(10) = -4

a + 9d = -4 ------(1)

A(22) = -16

a + 21d = -16 ------(2)

from equation (2) - (1)

12d = -12

d = -1

a = -4 - 9(-1) = -4 + 9 = 5

Now ,

A(38) = a + 37d

= 5 + 37(-1)

= 5 - 37

= -32

Answer 2

a + 9d = - 4 ---(1)

a + 21d = -16 ----(2)

by elimination method ...

a + 21d = - 16

a + 9d = - 4

________________

12d = -12

d = -1

a + 9(-1) = -4

a -9 = -4

a = 5

n = 38

an = a + (n - 1 ) d

= 5 + 37(-1)

= 5 - 37

= - 32

hope it helps