Question

{ y + 0.4x =4
{4x - y=2 ответ

​

Answer 1

$\left \{ {{y+0,4x=4} \atop {4x-y=2}} \right.=>\left \{ {{y=4-0,4x} \atop {y=4x-2}} \right.=>4x-2=4-0,4x\\\\4x-2=4-0,4x\\\\4x+0,4x=4+2\\\\4,4x=6\\\\x=6:4,4\\\\x=60:44\\\\x=\frac{60}{44}\\\\x=\frac{15}{11}\\\\x=1\frac{4}{11}$

$y=4x-2=4*\frac{15}{11}-2=\frac{60}{11}-\frac{22}{11}=\frac{38}{11}=3\frac{5}{11}$