(3 - 1 7/15)*5 + (2 - 1 5/16)*4 = (45/15 - 22/15)*5 + (32/15 - 21/16)*4 =
23/15*5 + 11/16*4 = 23/3 + 11/4 = 92/12 + 33/12 = 125/12 = 10 5/12
1) 500
2) 250
3) 100
4) 50
5) 25
6) 10
7) 5
8) 1
15:х=15
х=15:15
х=1
Вот так вот)
1м² = 100 дм²
9м² * 100 = 900 дм ²
78 + 3х - 25 = 104
3х + 78 - 25 = 104
3х + 53 = 104
3х = 104 - 53
3х = 51
х = 51 : 3
х = 17