Question

Three numbers in ap whose sum is 21 and their product is 280 are

Answer 1

Answer:

Step-by-step explanation:

Let the three numbers be a-d,a,a+d

Sum of the numbers = 21

a+a-d+a+d = 21

=> 3a=21

=>a=7

Product of the three numbers = 280

a(a-d)(a+d) = 280

7(7²-d²)=280

(49-d²)=40

d²=9

d=√9=±3

The three numbers = 4,7,10

Answer 2

Answer:

3a=21

a=7

(a-d)×a×(a+d)=280

(a×a-d×d)×a=280

(7×7-d×d)×7=280

(7×7-d×d)=280\7

(7×7-d×d)=40

d×d=49-40

d×d=9

d=3

hence the Ap is 3,6,9....