Question

Rozwiąż układy równań:

a)

b)

Answer 1

 

Answer 2

0.5x-0.5+y=-2.5

y=-x+7+1

 

0.5x-0.5-x+8=-2.5

y=-x+8

 

-0.5x=-10

y=-x+8

 

x=20

y=-20+8=-12

 

b)

(z-y)/3-(x+y)/2=0.5   /*6

x+y=3

 

2z-2y-3x-3y=3

x=3-y

 

2z-5y-3(3-y)=3

x=3-y

 

2z-5y-9+3y=3

x=3-y

 

2z-2y=12

x=3-y

 

z-y=6

x+y=3

---------

z+x=9

 

z-y=6

 

z+x=9

x+y=3

 

z=5

y=-1

x=4

Answer 3

1/2(x - 1) + y = - 5/2 (mnożymy przez 2)

x + y = 1 + 7

 

x - 1 + 2y = - 5

x + y = 8

 

x + 2y = -5 + 1

x + y = 8

 

x + 2y = -4 (mnożymy przez -1)

x + y = 8

-x - 2y = 4

x + y = 8

dodajemy stronami

-x + x - 2y + y = 4 + 8

-y = 12

y = -12

 

x + y = 8

x - 12 = 8

x = 8 + 12 = 20

odp

x = 20 , y = -12