Question

Решите систему уравнений

Answer 1

Ответ:

( 3;1)

Объяснение:

x^2-y^2=8

x-y=4

<=>

(x-y)(x+y)=8

x-y=4

<=>

4(x+y)=8

x-y=4

<=>

x+y=2

x-y=4

<=>

2x=6

x-y=4

<=>

x=3

3-y=4

<=>

x=3

y=-1

Ответ: 3; -1.

Answer 2

$\left \{ {{x^2-y^2=8} \atop {x+y=4}} \right.\\ \\x+y=4\\x=4-y\\\\(4-y)^2-y^2=8\\16-8y+y^2-y^2=8\\-8y=8-16\\-8y=-8 /:(-8)\\y=1\\\\x=4-1\\x=3\\\\\left \{ {{x=3} \atop {y=1}} \right. = > (3;1)$

Ответ: (3; 1)