Question

Potrzebuję na dziś układy równań !

Potrzebuję na dziś ! Układy równań !

a)

(x - y = 1

(2x + 3y = 7

b)

(-x + 2y = 1

(2x - 3y = 6

c)

(2x - y = 8

(x + 2y = -1

d)

(2x - y = -10

(2x - 3y = -18

e)

(x + 2y = -8

(-5x - 2y = -12

f)

(2x + y + 1 = 0

(3x + y - 16 = 0

Z góry dzięki :)

Answer 1

a)

{x-y=1 / * (-2) -> x-1=1

{2x+3y=7            x=1+1

x=2

{-2x+2y=-2

+{2x+3y=7

___________

5y=5/:5                                     {x=2

y=1                                           {y=1

 

b)

{-x+2y=1/*2 -> -x+2*8=1

{2x-3y=6          -x+16=1

-x=1-16

{-2x+4y=2      -x=-15/:(-1)

+{2x-3y=6         x=15

___________

y=8                                             {x=15

{y=8

c)

{2x-y=8/*2 -> 2*3-y=8

{x+2y=-1        6-y=8

-y=8-6

{4x-2y=16     -y=2/:(-1)

+{x+2y=-1       y=-2                                {x=3

__________                                          {y=-2

5x=15/:5

x=3

 

d)

{2x-y=-10/*(-1) -> 2x-4=-10

{2x-3y=-18           2x=-10+4

2x=-6/:2

{-2x+y=10         x=-3

+ {2x-3y=-18                                       {x=-3

___________                                      {y=4

-2y=-8/:(-2)

y=4

 

e)

{x+2y=-8   ->  5+2y=-8

+{-5x-2y=-12    2y=-8-5

__________     2y=-13/:2

-4x=-20/:(-4)   y=-6,5

x=5                                               {x=5

{y=-6,5

f)

{2x+y+1=0

{3x+y-16=0/*(-1)

 

{2x+y=-1/*(-1) -> 2*17+y=-1

{3x+y=16             34+y=-1

y=-1-34

{-2-y=1             y=-35

+{3x+y=16

_________

x=17                                       {x=17

{y=-35