244|61
244
1
ответ: 4
очень лёгкий пример
20+7*9=20+63=83
.......................................
20 <span>× 3 = 60
60 : 7 = 8.6
4 </span><span>× 21 = 84
84 : 100 = 8.4
8.4 + 4 = 12.4
19 </span><span>× 3 = 57
57 : 7 = 8.1
8.4 - 8.1 = 0.3
</span>
4,2х+1,7х-1,5х=7,92
4,4х=7,92
Х=7,92:4,4
Х=1,8