Question

If a + b + c = 5

4a + 2b + c = 11

9a + 3b + c = 19

Find the value of $a\times b\times c$.

__

Answer 1

a + b + c = 5 -------------------(1)

4a + 2b + c = 11 ----------------(2)

9a + 3b + c = 19 -----------------(3)

Multiplying 4 in equation 1 and subtract it from equation 2

-2b - 3c = 9

2b + 3c = 9-----------(4)

Multiplying 9 in equation 1 and subtract equation 3 from it

6b + 3c = 26-----------(5)

Solving equation 4 and 5

We get, b=3, c=1

Substituting b and c in equation 1

We get, a + b + c = 5, a + 3 + 1 = 5

a = 1

$a\times b\times c=1\times 3\times 1=3$