Question

resolver por el metodo de sustitucion

A- { x-y=4
       5x-y=0

Answer 1

$x-y=4---(1)\\\\ 5x+y=0---(2) \\\\ Despejamos(1): \\\\ x-y=4------------x=4+y ---(*) \\\\ Sustituimos,en (2): \\\\ 5(4+y)+y=4 \\\\ 20+5y+y=4 \\\\ 6y=4-20 \\\\ y= \frac{-16}{6}= -\frac{8}{3} \\\\ y=-\frac{8}{3} \\\\ Sustituimos, en (*): \\\\ x=4+y \\\\ x=4+(-\frac{8}{3}) \\\\ x=\frac{4}{3}$