Odpowiedzi

2010-01-25T19:16:56+01:00
1/2x + 1/4y = 4 /: 1/2
2/3x + 1/2y = 2 /:2/3

x+1/2y=2
x+3/4y=3

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

x+3/4*4=3
x=0



b) 2x + 4y = -7
4x - 3y = 8

c) y = 2x - 1
3(x+2) = 5(y-2)
Najlepsza Odpowiedź!
2010-01-25T19:24:08+01:00
1/2x-1/4y=4|*2
2/3x+1/2y=2

x-1/2y=8=> x=8+1/2y
2/3(8+1/2y)+1/2y=2

16/3+2/6y+1/2y=2
2/6y+3/6y=2-5 1/3
5/6y=-3 1/3|:5/6
y=-10/3*6/5
y=-4
x=8+1/2y
x=8-2
x=6

b)2x+4y=-7|:2
4x-3y=8

x=-7/2-2y
4(-7/2-2y)-3y=8
-14-8y-3y=8
-11y=22
y=-2
x=-3,5-2*(-2)
x=0,5

c)y=2x-1
3(x+2)=5(y-2)

3x+6=5(2x-1-2)
3x+6=10x-15
-7x=-21
x=3

y=2x-1
y=5