Question

4х+3у=48
4(30-3у)+3у=48

Answer 1

Ответ:

х=6

у=8

Пошаговое объяснение:

$\left \{ {{4x+3y=48}\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \atop {4(30-3y)+3y=48}} \right. \\\left \{ {{4x+3y=48}\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \atop {120-12y+3y=48}} \right. \\\left \{ {{4x+3y=48} \atop {120-9y=48}} \right.\\\left \{ {{4x+3y=48} \atop {-9y=48-120}} \right.\\\left \{ {{4x+3y=48} \atop {9y=72}\\\\\\\\\\\\\\} \right.\\\left \{ {{4x+3y=48} \atop {y=8}\\\\\\\\\\\\\\} \right.$

Подставим значение y в уравнение:

$4x+3*8=48\\4x+24=48\\4x=48-24\\4x=24\\x=24:4\\x=6$

Ответ: (х, у) = (6, 8)