Question

2x+3y=-7
3x+4y=-9
método da substituição ​

Answer 1

Resposta:

$2x = - 3y - 7 \\ x = ( \frac{ - 3y - 7}{2} ) \\ 3 \times ( \frac{ - 3y - 7}{2} ) + 4y = - 9 \\ - \frac{9}{3} y - \frac{21}{2} + 4y + 9 = 0 \\ \frac{3y}{3} - \frac{3}{2 } = 0 \\ y = \frac{3 \times 3}{3 \times 2 } \\ y = \frac{3}{2 } \\ logo. \\ x = \frac{1}{2} \times ( \frac{ - 3 \times 3}{2} - 7) \\ x = \frac{1}{2} \times \frac{ - 23}{2} \\ x = \frac{ - 23}{4}$

Boa sorte!