Question

find ABC if ab+3c =12 and ab-3c =4​

Answer 1

$ab + 3c = 12..... < 1 > \\ \\ ab - 3c = 4..... < 2 > \\ \\ add \: 1 \: and \: 2 \\ \\ 2ab = 16 \\ \\ ab = 8 \\ \\ from \: 1 \\ 3c = 4 \\ \\ c = \frac{4}{3} \\ \\ now \\ \\ abc \\ \\ = 8 \times \frac{4}{3} \\ \\ = \frac{32}{3}$

hope it helps

Answer 2

→ ab+3c=12 __________(1)

→ ab−3c=4 __________(2)

Add (1) and (2)

→ 2ab=16

→ ab=8

From (1)

→ 3c=4

→ $c = \frac{4}{3}$

Now,

→ $abc \: = 8 \times \frac{4}{3}$

→ $= \frac{32}{3}$