Question

The seventh term of an AP is -4 and 13 th term is -16 . find AP​

Answer 1

Step-by-step explanation:

as we know that, a7=-4

seventh term=a7

::a7=a+(n-1) d

::-4=a+(7-1) d

::-4=a+6d------------equation 1

in another term of 13th term.

the value of a13=-16

so, we write that,,

::a13=a+(n-1) d

::a13=a+(13-1) d

::-16=a+12d-----------equation 2

:;from equation 1 and 2

::a+12d=-16

::a+6d=-4

(-) (-) (+)

-----------------

6d=-12

d=-2

from equation 1

::a+6×-2=-4

a-12 =-4

a=-4+12

a=8

Thus, first number is 8 and difference is -2

Hence,sequence of AP=8,6,4,2,0...........