(-1 5//9*2 1//7+1 7//12)*1 1//7=(-14//9*15//7)+1 7//12)*1 1//7=(-10//3+19//12)*1 1//7=(-1.75)*1 1//7=-1.75*8//7=-2
// -черта дроби
(-1 5//9*2 1//7+1 7//12)*1 1//7=(-14//9*15//7)+1 7//12)*1 1//7=(-10//3+19//12)*1 1//7=(-1.75)*1 1//7=-1.75*8//7=-2
// -черта дроби