Odpowiedzi

2009-12-01T19:00:14+01:00
{3x+2y=13 |:(-2)
{2x+y=11

-1,5x-y=-7,5
2x+y=11
------------------------
0,5x=3,5 |:0,5

x=7
3*7+2y=13

x=7
2y=-8 |:2

x=7
y=-4


b.
{2x-3y=7 |*(-3)
{3x-5y=11 | *2

-6x+6y=-21
6x-10y=22
---------------
-4y=1 | :(-4)
y=-1/4

2x=7+3*(-1/4)
y--1/4

2x=6,25 |:2
y=-1/4

x=3,125
y=-1/4



2009-12-01T19:03:03+01:00
Odpowiedzi:
1.
{x =7
{y =-4

2.
{x = 3,125
{y = -0, 25