Question

the 16th term of an AP is 17 and 13th term is 38 find the 19th term​

Answer 1

Solution

let the first term is=a

last term is =l

and the difference is =d

now ...

a(16)=a+(16-1)d=17

=>a+15d=17......(1)

and ...

a+12d=38.........(2)

from equation(1 )and (2)...

a+15d=17

a+12d=38

___________

3d=-21

=>d=-7

now ....a=17-15(-7)=17+105=122

therefore the 19th term is ...

a(17)=122+(19-1)(-7)=122-126=-4

Hope this helps you......xd