Question

Tính

a)\(\dfrac{2}{5}\)+\(\dfrac{3}{8}\)-\(\dfrac{7}{20}\)

b)\(\dfrac{-5}{14}\)+\(\dfrac{3}{8}\)-\(\dfrac{1}{2}\)

Answer 1

a) 2/5 + 3/8 - 7/20

= 16/40 + 15/40 - 14/40

= 31/40 - 14/40

= 17/40

b) -5/14 + 3/8 - 1/2

= -20/56 + 21/56 - 28/56

= 1/56 - 28/56

= -27/56

Answer 2

\(a,\dfrac{2}{5}+\dfrac{3}{8}-\dfrac{7}{20}=\dfrac{16}{40}+\dfrac{15}{40}-\dfrac{14}{40}=\dfrac{17}{40}\)

\(b,\dfrac{-5}{14}+\dfrac{3}{8}-\dfrac{1}{2}=\dfrac{-40}{112}+\dfrac{42}{112}-\dfrac{56}{112}=\dfrac{-54}{112}=\dfrac{-27}{56}\)

Chúc pạn hok tốt!!~!!!

Answer 3

a ) 16/40+15/40-14/40=31/40-14/40=17/40