Question

If the sum of first three consecutive term of an AP is -42 and their product is -2394. Find the AP

Answer 1

Answer:

let the three consecutive numbers of AP are (a-d), (a), (a+d)

case1 : a-d+a+a+d=-42

3a=-42

a=-14

case2 : (a-d)(a)(a+d)=-2394

a (asquare-dsquare )=-2394

-14 [(-14)square-dsquare]=-2394

196-dsquare=171

dsquare=25

d=+,-5

when d=5

a-d=-14-5=-19

a=-14

a+d=-14+5=-9

when d=-5

a-d=-14+5=-9

a=-14

a+d=-14-5=-19

therefore the AP will be either

-19, -14, -9 or

-9, -14, -19