27/40 = (18х)/25
27 : 40 = (18х) : 25
40 * 18х = 25 * 27
720х = 675
х = 675 : 720
х = 675/720
х = 15/16
27/40 = (18х)/25
27 : 40 = (18х) : 25
40 * 18х = 25 * 27
720х = 675
х = 675 : 720
х = 675/720
х = 15/16