Question

Rozwiąż układy równań. Zapisz dokładne obliczenia. Pomóżcie, proszę!

Answer 1

2(x+y)-3(x+2)=2
3(x-y)+2(y+2)=2x-1

2x+2y-3x-6=2
3x-3y+2y+4=2x-1

-x +2y=8
x +y=-5
+ ---------------------------
0 3y=3
y=1
x+y=-5
x+1=-5
x=-5-1
x=-6

y=1
x=-6

b)
x+1/2y=7/2
x-y=-1 / * (-1)

x + 1/2y= 7/2
-x + y= 1
+ ======================
0 1,5y=4,5
y=3
x-y=-1
x-3=-1
x=-1+3
x=2

y=3
x=2


c)
7/x+2y=5/2x+y /* (x+2y)
5/3x+2=7/y+4

7=5(x+2y)/2x+y /*(2x+y)
5/3x+2=7/y+4

7(2x+y)=5x+10y
5/3x+2=7/y+4

14x+7y=5x+10y
5/3x+2=7/y+4

9x=3y
x=1/3y

5 7
--------- = ----------------
3*1/3+2 y+4


5 7
--- = ------- / *3
3 y+4

5= 21/y+4

5y+20=21
5y=21-20
5y=1
y=1/5


x=1/3*1/5

x=1/15
y=1/5