Tính giá trị của biểu thức: a) 85/54 - 10/36 x 14/5 b) 15/4 : 3/4 +11/7 c) 1/2 + 35/24 : 5/8
Giải thích
a) \[\frac{{85}}{{54}}{\rm{ - }}\frac{{10}}{{36}} \times \frac{{14}}{5}\] = \[\frac{{85}}{{54}}\] – \[\frac{7}{9}\] = \[\frac{{85}}{{54}}\] – \[\frac{{42}}{{54}}\]= \[\frac{{43}}{{54}}\]
b) \[\frac{{15}}{4}{\rm{ : }}\left( {\frac{3}{4} + \frac{{11}}{7}} \right)\] = \[\frac{{15}}{4}:\left( {\frac{{21}}{{28}} + \frac{{44}}{{28}}} \right)\] = \[\frac{{15}}{4}:\frac{{65}}{{28}}\]= \[\frac{{15}}{4} \times \frac{{28}}{{65}}\] = \[\frac{{21}}{{13}}\]
c) \[\frac{1}{2}{\rm{ + }}\frac{{35}}{{24}}{\rm{ : }}\frac{5}{8}\] = \[\frac{1}{2} + \frac{{35}}{{24}} \times \frac{8}{5}\]= \[\frac{1}{2} + \frac{7}{3}\] = \[\frac{3}{6} + \frac{{14}}{6}\]= \[\frac{{17}}{6}\]