Đáp án:
a,<=>$\left \{ {{6x+4y=-4} \atop {-x+4y=3}} \right.$
<=>$\left \{ {{7x=-7} \atop {-x+4y=3}} \right.$
<=> $\left \{ {{x=-1} \atop {1+4y=3}} \right.$
<=>$\left \{ {{x=-1} \atop {y=1/2}} \right.$
Vậy....
b,<=>$\left \{ {{3x=6} \atop {x-y=1}} \right.$
<=>$\left \{ {{x=2} \atop {y=1}} \right.$
Vậy ....
c,<=>$\left \{ {{10x-9y=1} \atop {10x+14y=24}} \right.$
<=>$\left \{ {{-23y=-23} \atop {10x-9y=1}} \right.$
<=>$\left \{ {{x=1} \atop {10-9y=1}} \right.$
<=>$\left \{ {{y=1} \atop {x=1}} \right.$
Vậy...
d,<=>$\left \{ {{3x-2y=-8} \atop {-4x+2y=10}} \right.$
<=> $\left \{ {{x=-2} \atop {-4.(-2)+2y=10}} \right.$
<=>$\left \{ {{x=-2} \atop {y=1}} \right.$
Vậy...
Giải thích các bước giải:
