the 7th term of ap is -4 and its 13 term is -16 find the ap Question the 7th term of ap is -4 and its 13 term is -16 find the ap in progress 0 Math Aubrey 2 months 2021-11-28T15:45:05+00:00 2021-11-28T15:45:05+00:00 2 Answers 0 views 0

## Answers ( )

Answer:The Answer is,

a=8

d=(-2)

The formula for nth term is,

an=a+(n-1)d

Hence substituting 7 in the place of n, we get,

a7=a(7-1) d

a7=a+6d…… (eq-1)

Similarly, Substituting 13 in the place of n, we get,

a13=a+(13-1)d

a13=a+12d…… (eq-2)

Subtracting Equation (2) from (1), we get,

-6d=12,

d=12/-6

d=-2

Hence substituting d=-2 in any of the equations

we get,

a=8

Hence the A. P is,

8,6,4,2,0,-2, -4, -6…..

Answer:Step-by-step explanation:given that7th term is -4,soa +6d =-4 let this be equation 1anda +12d = 13 let this be equation 2adding equation 1 and 2 we get## a+6d + a +12 d = -4 – 16

## 2a + 18d = -20

dividing the equation by 2 we geta +9d =-10therefore the 8th term is -10d = 8th term -7th termd= -10 +4d= -6substituting in eq 1 we geta+6(-6) =-4a-36=-4a= 32a+d = 32-6=26a+2d = 32-12 =20a+3d =32-18= 14therefore the AP is 32,26,20.14……….