Question

In the following AP: 100,85,70(k+20),40,25.....the value of k is

Answer 1

Answer:

k=-19

Step-by-step explanation:

100,85,70(k+20),40,25

here a=100

d=85-100=25-40=-15

so 3rd term

=70(k+20)

=100+2*(-15)

70k +1400=100-30

70k=-1400+70=-1330

k=-1330/70==-19

Answer 2

a=100

d=100-85

d=-15

Third term=70(k+20)and

a+2d

70(k+20)=a+2d

70k+1400=100-30

70k+1400=70

70k=70-1400

70k=-1330k

k=-1330/70

k=-19

hope u get ur answer..✌️