Odpowiedzi

2010-03-10T22:05:51+01:00
(a+b)/2=15
(a/2+b)/2=10

a+b=30
a/2+b=20

a+b=30 / *(-1)
a+2b=40

-a-b=-30
a+2b=40

b=10
a=20
:)
2010-03-10T22:06:30+01:00
X-y=15
-2x+y/2=10

x=15+y
-2(15+y)+1/2y=10

x=15+y
-30-2y+1/2y=10

x=15+y
-1 1/2y = 40 /: (-1 1/2)

x=15+y
y= -26 2/3

x=15-26 2/3
y= -26 2/3

x= -11 2/3
y= -26 2/3