Question

10+5(x-5y)=6(x-4y)

2x+3(y+5)=-5-2(2x+y)

розв'яжіть систему методом підстановки , допоможіть!

Answer 1

$\displaystyle\bf\\\left \{ {{10 + 5(x - 5y) = 6(x - 4y)} \atop {2x + 3(y + 5) = - 5 - 2(2x + y) }} \right. \\ \displaystyle\bf\\\left \{ {{10 + 5x - 25y = 6x - 24y} \atop {2x + 3y + 15 = - 5 - 4x - 2y }} \right. \\ \displaystyle\bf\\\left \{ {{5x - 25y - 6x + 24y = - 10} \atop {2x + 3y + 4x + 2y = - 5 - 15}} \right. \\ \displaystyle\bf\\\left \{ {{ - x - y = - 10} \atop {6x + 5y = - 20 }} \right. \\ \displaystyle\bf\\\left \{ {{x = 10 - y} \atop {6(10 - y) + 5y = - 20 }} \right. \\ \\ 60 - 6y + 5y = - 20 \\ - y = - 20 - 60 \\ - y = - 80 \\ y = 80 \\ \\ x = 10 - 80 \\ x = - 70$

Ответ: ( - 70 ; 80 )