Question

the fourth term of arithmetic progression is 15, 15 term is -29 find the 10 term

Answer 1

a+3d=15
a+14d=-29
11d=-44
d=-4
a-12=15
a=27
a+9d=27-36
        =-9
Tenth term is -9

Answer 2

T4 = 15

=> a + 3d = 15 --------(1)

T15 = - 29

=> a + 14d = - 29 ------(2)


On subtracting equation 1 from 2, we get

11d = - 44

=> d = - 4

On putting the value of d in equation 1, we get

a = 15+12

a = 27


T10 = a + 9d

= 27 + 9(-4)

= 27 - 36

= - 9