Question

розв'язати систему 8 клас​

Answer 1

Ответ:

Объяснение:

1) $\left \{ {{7x - 21 + 8 = 4 + 5x} \atop {4x - 4y - 7y = 6.5}} \right. \\\\\left \{ {{2x = 17} \atop {4x - 11y = 6.5}} \right. \\\\\left \{ {{x = 8.5} \atop {4 * 8.5 - 11y=6.5}} \right. \\\left \{ {{x = 8.5} \atop {11y=34-6.5}} \right. \\\\\left \{ {{x = 8.5} \atop {11y=27.5}} \right. \\\\\left \{ {{x = 8.5} \atop {y=2.5}} \right.$

2)$\left \{ {{4x+4y-3y=2} \atop {9x-18y-6x=-11}} \right. \\\left \{ {{4x+y=2} \atop {3x-18y=-11}} \right. \\\left \{ {{y=2-4x} \atop {3x-18(2-4x)=-11}} \right. \\\left \{ {{y=2-4x} \atop {3x-36+72x=-11}} \right. \\\left \{ {{y=2-4x} \atop {75x=25}} \right. \\\left \{ {{y=2-4x} \atop {x=\frac{1}{3} }} \right. \\\left \{ {{y=2-\frac{4}{3} } \atop {x=\frac{1}{3}}} \right. \\\left \{ {{y=\frac{2}{3} } \atop {x=\frac{1}{3}}} \right.$