Question

2a + 5b =-4
10a -3b =36
Doy corona ​

Answer 1

Respuesta:

$2a + 5b = - 4 \\ (2a + 5b = - 4) \times 5 \\ 10a + 25b = - 20 \\ 10a - 3b = 36 \\ - - - - - - - - \\10a + 25b - (10a -3b )= - 20 + 36 \\ 10a + 25b - 10a + 3b = 16 \\ 28b = 16 \\ b = \frac{4}{7} \\ 2a + 5b = - 4 \\ 2a + 5( \frac{4}{7} ) = - 4 \\ 2a + \frac{20}{7} = - 4 \\ 2a = - \frac{48}{7} \\ a = - \frac{24}{7}$