Question

Zadanie 3/101
Rozwiąż układy równań
a)
2x- 1/2y= 3
y- 4x = -6
b)
x-y+ 3
-5x + 10y= -10
c)
6x + y= 3
3x +1/2y= 5
d)
x-2y = -4
0,5x + y= 2

Answer 1

A)
2x-½y= 3
y- 4x = -6
{2x-½y=3/*2
{-4x+y=-6

{4x-y=6
{-4x+y=6
~~~~~~~~~~~~
____0=0
b)
x-y= 3/*5
-5x + 10y= -10
{5x-5y=15
{-5x+10y=-10
`````````````
_____5y=5/:5
_______y=1
x-y=3
x-1=3
x=4
{x=4
{y=1
c)
6x + y= 3
3x +½y= 5/*(-2)
{6x+y=3
{-6x-y=-10
```````````
____0≠-7
d)
x-2y = -4
0,5x + y= 2/*2
{x-2y=-4
{x+2y=4
``````````
__2x=0/:2
__x=0
x-2y=-4
-2y=-4/:(-2)
__y=2
{x=0
{y=2

Answer 2

A)
2x- 1/2y= 3
y- 4x = -6 y=4x-6
2x-1/2(4x-6)=3
0=0

b)
x-y= 3/*5 5x-5y=15
-5x + 10y= -10
5y=25
y=5
x-y=3
x=8

c)
6x + y= 3
3x +1/2y= 5/*-2 -6x-y=-5
0=8 rownanie sprzeczne

d)
x-2y = -4
0,5x + y= 2/*2 x+2y=4
2x=0/:2
x=0
y=2