Question

Решите способом подстоновки систему уравнений (1086-1099)

Answer 1

$\left \{ {{3x-y=1} \atop {3x+8y=19}} \right. \\\left \{ {{3x=1+y} \atop {3x+8y=19}} \right. \\1+y+8y=19\\y=2\\3x+8*2=19\\x=1\\(x, y) = (1,2)$