Odpowiedzi

2010-02-10T19:34:43+01:00
Z.1
x , y - szukane liczby oraz x > y
Mamy
x - y = 15
x / y = 3/2 ----> 2x = 3y ---> y = (2/3) x
-------------------
x - (2/3) x = 15
(3/3) x - (2/3) x = 15
(1/3) x = 15
x = 15 *3 = 45
45 - y = 15
y = 45 - 15 = 30
Odp. x = 45 oraz y = 30
z.2
a)
1 i 1/3 = 4/3 oraz 2 i 1/5 = 11/5
(4/3) : (11/5) = (4/3) * (5/11) = 20/33 = 20 : 33
b)
(18/15) : (13/ 5) = (18/15) * (5/13) = [18*5]/[15*13] = 18/39 =
= 18 : 39 = 6 : 13
c)2,5 : 7,5 = 25 : 75 = 1 : 3