А)
![\frac{3 \frac{1}{8}+2 \frac{1}{12}- \frac{1}{3} }{7,3-0,4*8,5}=1,25](https://tex.z-dn.net/?f=+%5Cfrac%7B3+%5Cfrac%7B1%7D%7B8%7D%2B2+%5Cfrac%7B1%7D%7B12%7D-+%5Cfrac%7B1%7D%7B3%7D++%7D%7B7%2C3-0%2C4%2A8%2C5%7D%3D1%2C25)
3 1/8 + 2 1/12 - 1/3 = 3 3/24 + 2 2/24 - 8/24 = 5 5/24 - 8/24 = 4 21/24 = 4 7/8
7,3 - 0,4 * 8,5 = 7,3 - 3,4 = 3,9
4 7/8 : 3,9 = 39/8 * 10/39 = 10/8 = 5/4 = 1 1/4 = 1,25
б)
![\frac{12*0,8-1,8}{2 \frac{1}{2}+2 \frac{1}{15}- \frac{1}{4}} =1 \frac{199}{259}](https://tex.z-dn.net/?f=+%5Cfrac%7B12%2A0%2C8-1%2C8%7D%7B2+%5Cfrac%7B1%7D%7B2%7D%2B2+%5Cfrac%7B1%7D%7B15%7D-+%5Cfrac%7B1%7D%7B4%7D%7D+%3D1+%5Cfrac%7B199%7D%7B259%7D+)
12 * 0,8 - 1,8 = 9,6 - 1,8 = 7,8
2 1/2 + 2 1/15 - 1/4 = 2 30/60 + 2 4/60 - 15/60 = 4 34/60 - 15/60 = 4 19/60
7,8 : 4 19/60 = 7 8/10 : 259/60 = 7 4/5 * 60/259 = 39/5 * 60/259 = 468/259 = 1 199/259