Question

bài 1:   Tính nhanh 

a/ -3/7 + 15 /26 - ( 2/13 - 3/7 )

b/ 2 3/7 + 2/9 - 1 3/7

c/ ( 377 /-231 - 124/89 + 34/791 ) x ( 1/6 - 1/8 - 1/24 )

 bài 2:       Thực hiện phép tính :

a/ 1/2 x ( 2/9 + 3/ 12 - 5/27 )                                         b/ ( -5/28 +1,75 + 8/35 ) : -3 9/20

c/ 1/3 x 5/7 - 3/2 x 26/14                                               d/ 70,5 - 528 : 15/2

Answer 1

B1:

a,\(\frac{-3}{7}+\frac{15}{26}-\left(\frac{2}{13}-\frac{3}{7}\right)\)

\(\Rightarrow\frac{-3}{7}+\frac{15}{26}-\frac{2}{13}+\frac{3}{7}\)

\(\Rightarrow\left(\frac{-3}{7}+\frac{3}{7}\right)+\frac{15}{26}-\frac{4}{26}\)

\(\Rightarrow\frac{15}{26}-\frac{4}{26}\)

=\(\frac{11}{26}\)

 

Answer 2

b,\(\frac{23}{7}+\frac{2}{9}-\frac{13}{7}\)

\(=\frac{23}{7}-\frac{13}{7}+\frac{2}{9}\)

\(=\frac{10}{7}+\frac{2}{9}\)

\(=\frac{104}{63}\)

Answer 3

c,\(\left(\frac{377}{-231}-\frac{124}{89}+\frac{34}{791}\right).\left(\frac{1}{6}-\frac{1}{8}-\frac{1}{24}\right)\)

\(=\left(\frac{377}{-231}-\frac{124}{89}+\frac{34}{791}\right).0\)

\(=0\)

Answer 4

(377/-231 - 124/89 + 34/791) . (1/6 - 1/8 - 1/24)

=(377/-231 - 124/89+34/791) . 0

=0