Question

1. (методом подстановки.) 2. (методом сложения.) 3. (любым методом.) решить хоть что-то из

Answer 1

1.
$\left \{ {{4x-5y=10} \atop {2x-2y=19}} \right. ; \left \{ {{2(19+2y) -5y=10} \atop {x= \frac{19+2y}{2} }} \right. ; \left \{ {{y=2} \atop {x= \frac{19+2y}{2} }}} \right. ; \left \{ {{38+4y-5y=10} \atop {x= \frac{19+2y}{2}}} \right. ; \left \{ {{-y=-28} \atop {x= \frac{19+2y}{2}}} \right.$
$\left \{ {{y=28} \atop {x= \frac{19+2*28}{2}}} \right. ; \left \{ {{x= \frac{75}{2} } \atop {y=28}} \right.$

2.
$\left \{ {{2x-2y=7} \atop {3x+2y=3}} \right. ; \left \{ {{2x-2y=7} \atop {2x+3x=7+3}} \right. ; \left \{ {{2x-2y=7} \atop {5x=10}} \right. ; \left \{ {{x=2} \atop {2*2-2y=7}} \right. ; \left \{ {{x=2} \atop {-4y=3}} \right. ; \left \{ {{x=2} \atop {y= -\frac{3}{4} }} \right.$

3.
$\left \{ {{2+3(x+5y)=-(2x+3y)} \atop {3x+4y=-8}} \right. \left \{ {{3x+2x+15y+3y=-2} \atop {3x+4y=-8}} \right. \left \{ {{5x+18y=-2} \atop {y= \frac{-3x-8}{4} }} \right.$
$\left \{ {{5x+18*\frac{-3x-8}{4}=-2} \atop {y= \frac{-3x-8}{4} }} \right. \left \{ {{5x-9*\frac{3x+8}{2}=-2|*2} \atop {y= \frac{-3x-8}{4} }} \right. \left \{ {{10x-9(3x+8)=-4} \atop {y= \frac{-3x-8}{4} }} \right.$
$\left \{ {{10x-18x-72=-4} \atop {y= \frac{-3x-8}{4} }} \right.\left \{ {{-8x=68} \atop {y= \frac{-3x-8}{4} }} \right.\left \{ {{ x=-\frac{17}{2} } \atop {y= \frac{3* \frac{17}{2} -8}{4} }} \right.\left \{ {{ x=-\frac{17}{2} } \atop {y= \frac{3*17-8*2}{4*2} }} \right.\left \{ {{ x=-\frac{17}{2} } \atop {y= \frac{35}{8} }} \right.$