Question

$y = x + 1$
$x + y = 9$
​

Answer 1

Объяснение:

$y = x + 1$

$x + y = 9$

$y = x + 1$

$x + x + 1 = 9$

$y = x + 1$

$2x = 8$

$y = x + 1$

$x = 4$

$y = 5$

$x = 4$