Question

Rozwiąż układy równań :

1.

x+y/2-y/3= 4

x-y/2+y/3= -3

2.

x+2/5-2y=5

x-y+2/6=3

Answer 1

1.

x+y/2-y/3= 4 /*6

x-y/2+y/3= -3 /*6

 

3x+3y-2y=24

3x-3y+2y=-18

 

3x+y=24

3x-y=-18

 

6x=6 /:6

x=1

 

3*1+y=24

x=1

 

y=24-3

x=1

 

y=21

x=1

2.

x+2/5-2y=5  /*5

x-y+2/6=3  /*6

 

x+2-10y=25

6x-y-2=18

 

x-10y=25-2

6x-y=18+2

 

x=23+10y

6x-y=20

 

x=23+10y

6*(23+10y)-y=20

138+60y-y=20

59y=20-138

59y=-118 /:59

y=-2

 

x=23+10*(-2)

x=23+(-20)

x=3

 

y=-2

x=3