Question

Решите систему, способом сложения и обьесните? ​

Answer 1

Объяснение:

5(2х - 3у) + 7у = -52

2(3х + 4у) - 6у = -4

10х - 15у + 7у = -52

6х + 8у - 6у = -4

10х - 8у = -52

6х + 2у = -4 | * 4

10х - 8у = -52

24х + 8у = -16

34х = -68

10х - 8у = -52

1)

34х = -68

х = -68 : 34

х = -2

2)

10х - 8у = -52

10 * (-2) - 8у = -52

-20 - 8у = -52

8у = -20 - (-52)

8у = -20 + 52

8у = 32

у = 32 : 8

у = 4

Ответ: (-2; 4)

Answer 2

$\displaystyle\bf\\\left \{ {{5(2x-3y)+7y=-52} \atop {2(3x+4y)-6y=-4}} \right. \\\\\\\left \{ {{10x-15y+7y=-52} \atop {6x+8y-6y=-4}} \right. \\\\\\\left \{ {{10x-8y=-52} \atop {6x+2y=-4}} \right.\\\\\\\left \{ {{5x-4y=-26} \atop {3x+y=-2} \ |\cdot4} \right. \\\\\\+\left \{ {{5x-4y=-26} \atop {12x+4y=-8}} \right. \\----------\\17x=-34\\\\x=-2\\\\y=-3x-2=-3\cdot (-2)-2=6-2=4\\\\\\Otvet \ : \ (-2 \ ; \ 4)$