Question

the sum of first 3 term of AP is 18.if the product of the 1st n the 3 rd term is 5 time the common difference find the 3 terms​

Answer 1

Answer:

Step-by-step explanation:

Let the three terms are

a-d,a,a+d

From 1st condition

a-d+a+a+d =18

:. 3a=18

a=18/3

:. a=6

From second condition

(a-d)(a+d)=5d

a square - d square =5d

36 - d^2=5d

36=5d+d²

d²+5d-36=0

d²+9d-4d-36=0

d(d+9)-4(d+9)=0

(d+9) (d-4) =0

d=(-9) or. d= 4

if d=-9

Then a-d=36-(-9)=36+9=45

a=36

a+d=36+(-9)=27

And if d=4

Then a-d =36-4=32

a=36

a+d=36+4=40

:. The three terma are 45,36,27. OR

32,36 ,40.