Решите систему уравнений 5x-y=7 3x+2y=-1

Question

Решите систему уравнений
5x-y=7
3x+2y=-1

Answer 1

5x-y=7
3x+2y=-1
--------------------
y=5x-7
3x+2y=-1
---------------------
y=5x-7
3x+2(5x-7)=-1
------------------------------
y=5x-7
3x+10x-14=-1
----------------------------
y=5x-7
13x=-1+14
------------------------
y=5x-7
13x=13
-------------------
y=5x-7
x=1
------------------
y=5-7, y=-2
x=1
--------------------------
/x,y/=/1,-2/
=============

Comments

спасибо

Answer 2

3x + 2(5x - 7) + 1 = 0
3x + 10x - 14 + 1 = 0
13x - 13 = 0
13x = 13
x = 1

Comments

спасибо большое