Question

Решите систему уравнений способом подстановки.
{ 5х – 3у = –1,
{ х + 2у = 5

Answer 1

$\displaystyle \left \{ {{5x-3y=-1} \atop {x+2y=5}} \right.\\ \\\left \{ {{5x-3y=-1} \atop {x=5-2y}} \right. \\\\5(5-2y)-3y=-1\\y=2\\x=5-2*2\\x=1\\(x,y)=(1,2)$