Question

1) 4x+3y=5
x-y=3
2) x-y=7
5x-3y=1
3) 6x+5y=6
2x+y=-2
Это система

Answer 1

{4x+3y=5
{x-y=3|*3
+{4x+3y=5
+{3x-3y=9
7x=14|:7
x=2
2-y=3
-y=3-2
-y=1|:(-1)
y=-1
{x-y=7|*5
{5x-3y=1
-{5x-5y=35
-{5x-3y=1
-2y=34|:(-2)
y=-17
x-(-17)=7
x=7-17
x=-10
{6x+5y=6
{2x+y=-2|*3
-{6x+5y=6
-{6x+3y=-6
2y=12|:2
y=6
2x+6=-2
2x=-2-6
2x=-8|:2
x=-4