А -b + 3b - c + a = 2a + 2b - c = 2(a+b) -c
<span> 5 2/5а - 3 7/15а + 7 7/10а=5 12/30а+3 14/30а+7 21/30а=15 47/30а= 16 17/30а
</span><span>при а=1 37/578
</span>1 37/578 * 16 17/30=616/578*497/30=308*497/578*15=153076/8670=17 5686/8670= 17 2843/4335
1) 15:9=1 ( 6 ост.)
2) 8:9=0 ( 8 ост.)
0,29+0,69=0,98
24,78-3,17+4,96=6,57
0,46-0,18=0,28
12,83-4,54-5,17=3,12