Question

решите системы уравнений
а) способом подстановки
б) способом сложентя
помогите у меня сор​

Answer 1

Ответ: a) x=1/2, y=1

б) x=2, y=-1

Пошаговое объяснение:

a) Способом подстановки

$\left \{ {{4x+y=3} \atop {6x-2y=1}} \right. \\\left \{ {{y=3-4x} \atop {6x-2(3-4x)=1}} \right. \\\left \{ {{y=3-4x} \atop {6x-6+8x=1}} \right. \\\left \{ {{y=3-4x} \atop {14x=1+6}} \right. \\\left \{ {{y=3-4x} \atop {x=7/14}} \right. \\\left \{ {{y=3-4*(1/2)} \atop {x=1/2}} \right. \\\left \{ {{y=1} \atop {x=1/2}} \right.$

б) Способом сложения

$\left \{ {{3x-y=7} \atop {2x+3y=1}} \right.\\\left \{ {{3x-y=7} \atop {2x+3y=1}|*-1} \right.\\\left \{ {{3x-y=7} \atop {-2x-3y=-1}} \right.\\\left \{ {{3x-y=7} \atop {-2x-3y=-1}} \right. |+\\\left \{ {{3x-y-2x-3y=7-1} \atop {-2x-3y=-1}} \right.\\\left \{ {{x-4y=6} \atop {3x-y=7}} \right.\\\left \{ {{x=6+4y} \atop {3(6+4y)-y=7}} \right.\\\\\left \{ {{x=6+4y} \atop {18+12y-y=7}} \right.\\\\\left \{ {{x=6+4y} \atop {11y=7-18}} \right.\\\\\left \{ {{x=6+4y} \atop {11y=-11}} \right.$

$\left \{ {{x=6+(-1*4)} \atop {y=-1}} \right. \\\left \{ {{x=2} \atop {y=-1}} \right.$