Question

x + 3y = 7
4x + y = 13
Sustitución o eliminación plis urg

Answer 1

Explicación paso a paso:

$1)x + 3y = 7 \\ x = 7 - 3y$

$4(7 - 3y) + y = 13 \\ \\ 28 - 12y + y = 13 \\ - 12y + y = 13 - 28 \\ - 11y = - 15 \\ 11y = 15 \\ y = \frac{15}{11}$

$x = 7 - 3y = 7 - 3 \times \frac{15}{11} \\ = 7 - \frac{45}{11} = \frac{77}{11} - \frac{45}{11} = \frac{32 }{11} \\ x = \frac{32}{11}$

$\frac{32}{11} \ + 3 \times \frac{15}{11} = \frac{32}{11} + \frac{45}{11} = \frac{77}{11} = 7$