Question

The sum of three no in



a.P is 15 and the products of of first and last is 21. Find the numbers.

Answer 1

let (a-d),a,(a+d) be three numbers.

sum=15

3a=15

a=5

(a-d)(a+d)=21

${a}^{2} - {d}^{2} = 21$

$25 - {d}^{2} = 21$

${d}^{2} = 4$

d=2
numbers are 3,5,7