Question

[Nguyễn Hải Băng]

 Thực hiện phép tính ( tính nhanh nếu có thể ):

a, ( -3/4 + 5/13 ) : 2/7 - ( 9/4 + 8/13 ) : 2/7

b, (-12 . 2/7 + 8/9 : 7/2 - 2/7 . 5/18 ) . 7/2

c, 45/4 - ( 19/7 + 21/4 )

d, -1/4 . 152/11 - 0,25 . 68/11

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(=\dfrac{7}{2}\left(-\dfrac{3}{4}+\dfrac{5}{13}-\dfrac{9}{4}-\dfrac{8}{13}\right)=\dfrac{7}{2}\cdot\left(-3-\dfrac{3}{13}\right)=\dfrac{7}{2}\cdot\dfrac{-42}{13}=\dfrac{-147}{13}\)

b: \(=-12+\dfrac{8}{9}-\dfrac{5}{18}=\dfrac{-216}{18}+\dfrac{16}{18}-\dfrac{5}{18}=\dfrac{-205}{18}\)

c: \(=\dfrac{45}{4}-\dfrac{19}{7}-\dfrac{21}{4}=6-\dfrac{19}{7}=\dfrac{23}{7}\)

d: \(=\dfrac{-1}{4}\left(\dfrac{152}{11}+\dfrac{68}{11}\right)=\dfrac{-1}{4}\cdot20=-5\)