Question

x + 2y = 20 x - y = 5

Answer 1

Respuesta:

$x + 2y = 5 \\ 20x - y = 5 \\ \\ - 20x - 40y = - 100 \\ 20x - y = 5 \\ \\ - 41y = - 95 \\ \\ y = \frac{95}{41} \\ \\ x + 2 \times \frac{95}{41} = 5 \\ \\ x = \frac{15}{41} \\ 5 + 5 = 5 \\ \\ = 0.5$