(5×5)+5×5=50
это все просто
1/3х + 5/9х = 7,2,
3/9х + 5/9х = 7,2,
8/9х = 7,2,
х = 7,2 : 8/9,
х = 7,2 * 9/8,
х = 8,1
(a+b):c | 365 | 207 | 100 | 1250 |
a:c+b:c | 365 | 207 | 100 | 1250 |
<span>х(1/12+1)=39
</span>х *13/12=39
x = 12/13*39 = 12*3 =36
x =36