Question

Реши систему уравнений методом подстановки: x−2y=−2
7x−10y=7

Answer 1

x−2y=−2
7x−10y=7


x=2у−2
7*(2у−2)−10y=7


x=2у−2
14у−14−10y=7


x=2у−2
4у=21

x=2*21/4−2 = 21/2 - 2 = 10,5-2 = 8,5
у = 21/4

Ответ:(8,5; 21/4)

Answer 2

$x - 2y = - 2 \\ 7x - 10y = 7$
$x = 2y - 2 \\ 7x - 10y = 7$
$14y - 14 - 10y = 7 \\ 4y = 21 \\ y = \frac{21}{4} = \frac{525}{100} = 5.25$
$x = 2y - 2 = 10.5 - 2 = 8.5$