Question

Решите систему уравнений методом подстановки номер 1084 г)д)е)

Answer 1

Буква Г.
$\left \{ {{13x-12y=14} \atop {11x-4=18y}} \right. { {{|*(-3)} \atop {|*2}} \right. \left \{ {{-39x+36y=-42} \atop {36y=22x-8}} \right. \left \{ {{-39x+22x-8=-42} \atop {18y=11x-4}} \right. \left \{ {{-17x=-34} \atop {18y=11x-4}} \right. \\ \left \{ {{x=2} \atop {y=1}} \right.$
Ответ: $(2;1)$

Буква Д.
$\left \{ {{10x-9y=8} \atop {21y+15x=0.5}} \right. { {{|*3} \atop {|*2}} \right. \left \{ {{30x=27y+24} \atop {42y+30x=1}} \right. \left \{ {{30x=27y+24} \atop {42y+27y+24=1}} \right. \left \{ {{30x=27y+24} \atop {69y=-23}} \right. \\ \left \{ {{30x=-9+24} \atop {y=- \frac{1}{3} }} \right. \left \{ {{x= \frac{1}{2} } \atop {y=- \frac{1}{3} }} \right.$
Ответ: $( \frac{1}{2};- \frac{1}{3} )$

Буква Е.
$\left \{ {{9y+8z=-2} \atop {5z=-4y-11}} \right. { {{|*5} \atop {|*8}} \right. \left \{ {{45y+40z=-10} \atop {40z=-32y-88}} \right. \left \{ {{45y-32y-88=-10} \atop {5z=-4y-11}} \right. \left \{ {{y=6} \atop {5z=-24-11}} \right. \left \{ {{y=6} \atop {z=-7}} \right.$
Ответ: $(6;-7)$