Question

[Nguyễn Thu Thuỷ]

B3 : 
a, 2/3 + 1/5 x 10/7 
b, 7/12 - 27/7 x 1/18 
c, (23/11 - 15/82) x 41/25 
d, (4/5 + 1/2) (3/13-8/13) 
giúp em vs ạa

Answer 1

[subjects]

\(a.\dfrac{2}{3}+\dfrac{1}{5}\cdot\dfrac{10}{7}\\ =\dfrac{2}{3}+\dfrac{2}{7}=\dfrac{20}{21}\\ b.\dfrac{7}{12}-\dfrac{27}{7}\cdot\dfrac{1}{18}\\ =\dfrac{7}{12}-\dfrac{3}{14}=\dfrac{31}{84}\\ c.\left(\dfrac{23}{11}-\dfrac{15}{82}\right)\cdot\dfrac{41}{25}\\ =\dfrac{1721}{902}\cdot\dfrac{41}{25}=\dfrac{1721}{550}\\ d.\left(\dfrac{4}{5}+\dfrac{1}{2}\right)\cdot\left(\dfrac{3}{13}-\dfrac{8}{13}\right)\\ =\dfrac{13}{10}\cdot\left(\dfrac{-5}{13}\right)=\dfrac{-1}{2}\)