Question

arithmetic progression a1=?, a3=x+7, a7=x+49 ​

Answer 1

Answer:

a3 = x+7 = a1+2d. ....1

a7 = x+49= a1 +6d. ....2

multiply 1 by 3 then subtract 2 eqn from it

we get 2a = 2x -28

a = (2x-28)/2

a = x-14

hope this will help you