256-16=240 3+14=17 17+240=257
x+32+y+13=x+y+45
a+98+49=a+147
m-98+n+56=m+n+154
1л-5ст. воды
2*10-?
1) 10*5=50ст в одном ведре
2) 2*50=100 ст в 2 ведрах
по моему так
1.
8 2/26 = 210/26 = 630/78
5 7/39 = 202/39 = 404/78
630/78 - Х = 404/78
Х = 630/78 - 404/78 = 226/78 = 2 70/78 = 2 35/39
2.
5 5/33 = 170/33 = 680/132
8 3/44 = 355/44 = 1065/132
680/132 + У = 1065/132
У = 1065/132 - 680/132 = 385/132 = 2 121/132 = 2 11/12