Question

Ina n Ap the 3rd ter and 7th terms are 14 -2 respectively which term of the Ap is -14​

Answer 1

Given:-

• a+2d=14-(1)
• a+6d= -2-(2)

To find:-

• which term of AP is -14

Solution:-

solve eq (1) and (2)

a+6d= -2

a+2d= 14

.- - -

4d=-16

d=-4

hence , common difference is -4

put in eq (1)

a+2d=14

a+2×(-4)=14

a-8=14

a=22

hence ,first term of AP is 22

Now ,which term of AP is -14 ?

a(n)=a+(n-1)d

-14=22+(n-1)(-4)

-14-22=(n-1)(-4)

(-36) ÷( -4 )=n-1

9=n-1

10= n

hence the 10 term of AP is -14

verification

a(n)=a+(n-1)d

a(n)=22+(10-1)(-4)

a(n)=22+9(-4)

a(n)=22-36

a(n)= - 14

hence ,verified

Thanks

$hope\:its\:helpful$