Răspunsuri

2014-10-07T18:32:07+03:00
15*(18-x)=180
18-x=180/15
18-x=12
x=18-12
x=6

63:(x-2)=7
63=7x-14
63+14=7x
77=7x
x=77/7
x=11

14x+28x=588

42x=588
x=588/42
x=15