Решите систему уравнений методом подстановки: а) {4x-5y=10 3x+2y=19 б)...

Решите задачу:

$\left \{ {{4x-5y=10} \atop {3x+2y=19}} \right. \\ \left \{ {{4x=5y+10} \atop {3x+2y=19}} \right. \\ \left \{ {{x=1,25y+2,5} \atop {3x+2y=19}} \right. \\ 3*(1,25y+2,5)+2y=19\\ 3,75y+7,5+2y=19\\ 5,75y=11,5\\ y=2\\ x=1,25*2+2,5=5\\$

$\left \{ {{2+3(x+5y)=-(2x+3y)} \atop {3x+4y=-8}} \right. \\ \left \{ {{2+3(x+5y)=-(2x+3y)} \atop {4y=-8-3x}} \right. \\ \left \{ {{2+3(x+5y)=-(2x+3y)} \atop {y=-2-0,75x}} \right. \\ 2+3(x+5*(-2-0,75x)=-(2x+3*(-2-0,75x))34\\ 2+3x-30-11,25x=-2x+6+2,25x\\ -28-8,25x=6+0,25x\\ 8,5x=-34\\ x=-4\\ y=-2-0,75*(-4)=1$