Question

Помогите плииииз !!!

Answer 1

Пошаговое объяснение:

$<strong><em><u>1.</u></em></strong><strong><em><u> </u></em></strong><strong><em><u>1</u></em></strong><strong><em><u>)</u></em></strong>x = 2y + 5 \\ 2x - 3y = - 4 \\ .......................... \\ x = 2y + 5 \\ 2(2y + 5) - 3y = - 4 \\ 4y + 10 - 3y = - 4 \\ y = - 14 \\ ............................ \\ x = 2 \times ( - 14) + 5 = - 28 + 5 = - 23 \\ <strong><em><u>2</u></em></strong><strong><em><u>)</u></em></strong> - x - 4y = - 5 \\ 2x + 7y = 8 \\ .................... \\ - x = 4y - 5 \\ x = 5 - 4y \\ ........................ \\ 2 \times ( 5 - 4y) + 7y = 8 \\ 10 - 8y + 7y = 8 \\ - y = - 2 \\ y = 2 \\ ....................... \\ x = 5 - 4 \times2 = 5 - 8 = - 3$

Первое сделано на фото)

2.1)2x-3y=1

3x+y=7 (*3)

2x-3y=1

9x+3y=21

11x=22

x=2

3*2+y=7

y=7-6

y=1

2)x+5y=7 *(-3)

3x+2y=-5

-3x-15y=-21

3x+2y=-5

-13y=-26

y=2

x+5*2=-5

x=-5-10

x=-15