Question

In ap 3rd terms is 12 and 50th term 73 find its 31st term

Answer 1

Using elimination method,

a+2d=12

a+49d=73

(-)(-) (-)

__________

X - 47d=-61

d=61/47

Put d=61/47 in equ1

a+2×61/47=12

a=12-122/47

$12 - \frac{122}{47}$



then find the value of a and substitute the value of a and d in a31