5/3+(-2.7)-(-1.2) =5/3+(-2.7)+1.2 =5/3+(-1.5) =1/6
còn 1 phép tínhnữa mà bạn ơi giải nốt đi ! please ~
thực hiện các phép tính bằng cách hợp lý nhất : a) 5/3 + ( -2/7) - (1,2)
b) -4/9 + (-5/6) -17/4a,5/3+(-2/7)-(-1,2) b,-4/9+(-5/6)-17/4
=5/3-2/7+1,2 =-4/9-5/6-17/4
=29/21+6/5=271/105 =-23/18-17/4
=-199/36
a, \(\dfrac{5}{3}+\left(\dfrac{-2}{7}\right)-\left(\dfrac{-1}{2}\right)\)
\(=\dfrac{5}{3}-\dfrac{2}{7}+\dfrac{1}{2}\)
\(=\dfrac{29}{21}+\dfrac{1}{2}\)
\(=\dfrac{79}{42}\)
b, \(\dfrac{-4}{9}+\left(\dfrac{-5}{6}\right)-\dfrac{17}{4}\)
=\(\dfrac{-4}{9}-\dfrac{5}{6}-\dfrac{17}{4}\)
\(=\dfrac{-23}{8}-\dfrac{17}{4}\)
\(\dfrac{-199}{36}\)
\(a,\dfrac{5}{3}+\left(-\dfrac{2}{7}\right)-\left(-1,2\right)\)
\(=\dfrac{5}{3}+\left(-\dfrac{2}{7}\right)-\left(-\dfrac{6}{5}\right)\)
\(=\dfrac{5}{3_{\left(35\right)}}+\left(-\dfrac{2}{7_{\left(15\right)}}\right)+\left(\dfrac{6}{5_{\left(21\right)}}\right)\)
\(=-\left(\dfrac{175+30+126}{105}\right)\)
\(=-\dfrac{331}{105}\)
\(b,\left(-\dfrac{4}{9}\right)+\left(-\dfrac{5}{6}\right)-\dfrac{17}{4}\)
\(=\left(-\dfrac{4}{9_{\left(4\right)}}\right)+\left(-\dfrac{5}{6_{\left(6\right)}}\right)-\dfrac{17}{4_{\left(9\right)}}\)
\(=\dfrac{\left(-16\right)+\left(-30\right)-153}{36}\)
\(=-\dfrac{199}{36}\)