Ответ:
1. \((4.8+2.7)\cdot0.6+1.5:0.3=7.5\cdot0.6+5=4.5+5=9.5\).
2. \(\left(7\frac{1}{8}+1\frac{3}{8}\right):\frac{1}{4}-5\frac{1}{2}=8\frac{4}{8}:\frac{1}{4}-5\frac{1}{2}=8\frac{1}{2}\cdot4-5\frac{1}{2}=34-5\frac{1}{2}=28\frac{1}{2}\).
3. \(12.6:(2.4+1.6)\cdot3-4.5=12.6:4\cdot3-4.5=3.15\cdot3-4.5=9.45-4.5=4.95\).
4. \(\left(\frac{5}{6}-\frac{1}{3}\right)\cdot12+2\frac{3}{4}=\frac{1}{2}\cdot12+2\frac{3}{4}=6+2\frac{3}{4}=8\frac{3}{4}\).
Ответ: 1) 9,5; 2) 28 1/2; 3) 4,95; 4) 8 3/4.
