Question

Розв'я яжить систему рівнянь підстановки 3x-5у=7
2х-7у=-10​

Answer 1

Ответ:

х=9; у=4

Объяснение:

все розписано на фото

Answer 2

$\displaystyle\bf\\\left \{ {{3x-5y=7} \atop {2x-7y=-10 \ |:2}} \right. \\\\\\\left \{ {{3x-5y=7} \atop {x-3,5y=-5}} \right. \\\\\\\left \{ {{x=3,5y-5} \atop {3\cdot(3,5y-5)-5y=7}} \right.\\\\\\\left \{ {{x=3,5y-5} \atop {10,5y-15-5y=7}} \right. \\\\\\\left \{ {{x=3,5y-5} \atop {5,5y=7+15}} \right. \\\\\\\left \{ {{x=3,5y-5} \atop {5,5y=22}} \right. \\\\\\\left \{ {{x=3,5\cdot 4-5} \atop {y=4}} \right. \\\\\\\left \{ {{x=14-5} \atop {y=4}} \right.$

$\displaystyle\bf\\\left \{ {{x=9} \atop {y=4}} \right. \\\\\\Otvet \ : \ (9 \ ; \ 4)$