480/2=240
240/2=120
480-120=360
проверка 360+120=480
<span>15c+45-12=78
15с+45=78+12
15с=90-45
15с=45
с=45:15
<u>с=3 </u>
15*3+45-12=78
78=78, верно</span>
B × 5 = 1021 - 796
b × 5 = 225
b = 225 : 5
b = 45
-------------------------
45x5=1021-796
45x5=225
225=225
a:6 = 1224 - 859
а : 6 = 365
а = 365 × 6
а = 2190
---------------------
2190:6=1224-859
2190:6=365
365=365