o sa le notez cu a) , b) si asa mai departe pentru a nu le incurca
a) 8/x = 4/ 3
x= 8 * 3 / 4
x= 24 / 4 = 6
b) 3/7 = x / 28
x = 3 * 28 / 7
x = 84 / 7 = 12
c) 15 / 18 = 5 / x
x = 18 * 5 / 15
x = 90 / 15 = 4
d) x/6 = 2
x = 6 * 2 = 12
e) 7 = x/ 3
x = 7 * 3 = 21
f) 9/x = 3
x = 9 / 3 = 3
g) 6 = 4/x
x= 4/ 6 ( simplificam cu 2 )
x = 2/ 3
h) 8/x = 4/ 3
x= 8 * 3 / 4
x= 24 / 4 = 6
i) 10/14 = x / 7
x= 10* 7 / 14
x= 70 / 14 = 5