Question

determine 3 numbers in arithmetic progression whose sum is 15 and product is 80

Answer 1

Answer:

Let the first term be a and common difference be d.

Let the 3 terms be:

a-d, a, a+d

a-d+a+a+d = 15

3a = 15

a = 5

(a-d)(a)(a+d) = 80

(5-d)(5)(5+d) = 80

(25-5d)(5+d) = 80

125 + 25d - 25d - 5d^2 = 80

125 - 5d^2 = 80

5d^2 = 45

d^2 = 9

d = 3

Thus, the three terms are 2, 5, 8

Hope this helps you.