Question

Tính bằng cách hợp lí :

S= 3/4 - 0,25 - [ 7/3 + ( -9/2 )] - 5/6

Answer 1

\(S=\dfrac{3}{4}-\dfrac{1}{4}-\left(\dfrac{7}{3}-\dfrac{9}{2}\right)-\dfrac{5}{6}\)

\(=\left(\dfrac{3}{4}-\dfrac{1}{4}+\dfrac{18}{4}\right)-\left(\dfrac{14}{6}+\dfrac{5}{6}\right)\)

\(=\dfrac{20}{4}-\dfrac{19}{6}=\dfrac{11}{6}\)

Answer 2

\(S=\dfrac{3}{4}-0,25-\left[\dfrac{7}{3}+\left(\dfrac{-9}{2}\right)\right]-\dfrac{5}{6}\)

   \(=\dfrac{3}{4}-0,25 +\dfrac{13}{6}-\dfrac{5}{6}\)

   \(=\dfrac{11}{6}\)