Question

Algebradan yordam berila iltimos

Answer 1

Ответ:

№4

1)

$7x + 4y = 29 \\ 5x + 2y = 19$

Keyin birinchi tenglama bilan ikkinchi tenglamani ayiramiz. Ya’ni :

$2x + 2y = 10$

Tenglamani ikkiga bõlamiz |÷2

$x + y = 5 \\ x = 5 - y$

"x" õrniga «5-y»ni qõyamiz.

$7(5 - y) + 4y = 29 \\ 35 - 7y + 4y = 29 \\ - 3y = - 6 \\ y = 2$

Endi X ni topamiz.

X = 5 - y. => X = 5 - 2 = 3

Javob: X = 3; Y = 2.

2)

$5x - 4y = 13 \\ 2x - y = 4$

$5x - 4y = 13 \\ y = 2x - 4$

$5x - 4(2x - 4) = 13 \\ 5x - 8x + 16 = 13 \\ - 3x = - 3 \\ x = 1$

$y = 2x - 4 \\ y = 2 \times 1 - 4 \\ y = - 2$

Javob: X = 1; Y = -2