Question

3x + 3y = 12000
2x + 3y = 28800​

Answer 1

$3x \: + 3y = 12000 \\ - (2x \: + 3y) = 28800 \\ \\ x = - 16800 \\ \\ 2( - 16800) + 3y = 28800 \\ 3x = 62400 \\ \\ y = 20800$

Answer 2

Step-by-step explanation:

3y=12000

−(2x+3y)=28800

x=−16800

2(−16800)+3y=28800

3x=62400

y=20800