Question

{3x+2y=100
{x - y = 210​

Answer 1

Resposta:

${3x + 2y = 100} \\ {x - y = 210} \: \: \: \: \: \: \: \: ( \times 2) \\ - - - - - - - - - - \\ 3x + 2y = 100 \\ 2x - 2y = 420 \\ - - - - - - - - - - \\ 5x = 520 \\ x = \frac{520}{5} \\ x = 104 \\ \\ 3x + 2y = 100 \\ 3 \times 104 + 2y = 100 \\ 312 + 2y = 100 \\ 2y = 100 - 312 \\ 2y = - 212 \\ y = \frac{ - 212}{2} \\ y = - 106$