Odpowiedzi

2009-11-28T16:15:43+01:00
X+(7+x)
______________=20 |*2
2

x+7+x = 40

2x = 37

x = 18,5
2 3 2
2009-11-28T16:16:24+01:00
1) x+(7+x)
----------------------
x+7+x
2x+7
---------------------------
2)2x+7=20
=========================
2x=20-7
2x=13
13/2=6,5
x=6,5
1 1 1
2009-11-28T16:15:58+01:00
0,5x + 3,5 + 0,5x = 20
x +3,5 = 20
x = 16,5

lub

x+(7+x)
______________=20 | *2
2

x+7+x = 40 |-7

2x = 33

x = 16,5
1 4 1