Question

Упражнения
1261. 1)
Найдите решение систем уравнений (1261—1263):
2х - 3y+1+ (х - у + 5) = 0,
5х + 7y - 7 - (8х + y + 1) = 0;
2)
7х + 9y - 14 + (у - 5x - 11) + 3 = 0,
11х + y - 9 + (4y - 9x - 7) = 0.​

Answer 1

Ответ:

1) $y=1, x=-\frac{2}{3}$

2) $x=5, y=\frac{6}{5}$

Пошаговое объяснение:

1) $\left \{ {{2x- 3y+1+ (x - y + 5) = 0,} \atop {5x + 7y - 7 - (8x + y + 1) = 0}} \right.$

$\left \{ {{3x- 4y+6 = 0,} \atop {-3x + 6y - 8 = 0}} \right.$

$\left \{ {{3x= 4y-6,} \atop {-3x + 6y - 8 = 0}} \right.$

$-(4y-6)+6y-8=0$

$2y-2=0$

$y=1$

$x=\frac{4y-6}{3}$

$x=\frac{4-6}{3} =-\frac{2}{3}$

2) $\left \{ {{7x + 9y - 14 + (y - 5x - 11) + 3 = 0} \atop {11x + y - 9 + (4y - 9x - 7) = 0}} \right.$

$\left \{ {{x+5y-11=0} \atop {2x+5y-16 = 0}} \right.$

$\left \{ {{5y=-x+11} \atop {5y = -2x+16}} \right.$

$-x+11=-2x+16$

$x=5$

$y=\frac{-x+11}{5}$

$y=\frac{-5+11}{5}=\frac{6}{5}$