Violympic toán 6

nguyen ngoc son

1.thực hiện phép tính

a.\(\frac{-1}{12}-\left(2^5_8-\frac{1}{3}\right)\)

b.-1,75-\(\left(\frac{-1}{9}-2^1_{18}\right)\)

c.\(\frac{2}{5}+\frac{-4}{3}+\frac{-1}{2}\)

d.\(\frac{3}{12}-\left(\frac{6}{15}-\frac{3}{10}\right)\)

e.\(\left(8^5_{11}+3^5_8\right)-3^5_{11}\)

f.\(\frac{4}{9}:\left(\frac{-1}{7}\right)+6^5_9:\left(\frac{-1}{7}\right)\)

g.\(\frac{-1}{4}.13^9_{11}-0,25.6^2_{11}\)

h.\(5^{27}_5+\frac{27}{23}+0,5-\frac{5}{27}+\frac{16}{23}\)

i.\(\frac{3}{8}.27^1_5-51^1_5.\frac{3}{8}+19\)

Nguyễn Lê Phước Thịnh
2 tháng 7 2020 lúc 10:00

a) Ta có: \(\frac{-1}{12}-\left(2\frac{5}{8}-\frac{1}{3}\right)\)

\(=-\frac{1}{12}-\frac{21}{8}+\frac{1}{3}\)

\(=\frac{-6}{72}-\frac{189}{72}+\frac{24}{72}\)

\(=-\frac{19}{8}\)

b) Ta có: \(-1,75-\left(\frac{-1}{9}-2\frac{1}{18}\right)\)

\(=\frac{-7}{4}+\frac{1}{9}+\frac{37}{18}\)

\(=\frac{-63}{36}+\frac{4}{36}+\frac{74}{36}\)

\(=\frac{5}{12}\)

c) Ta có: \(\frac{2}{5}+\frac{-4}{3}+\frac{-1}{2}\)

\(=\frac{12}{30}+\frac{-40}{30}+\frac{-15}{30}\)

\(=-\frac{43}{30}\)

d) Ta có: \(\frac{3}{12}-\left(\frac{6}{15}-\frac{3}{10}\right)\)

\(=\frac{3}{12}-\frac{6}{15}+\frac{3}{10}\)

\(=\frac{15}{60}-\frac{24}{60}+\frac{18}{60}\)

\(=\frac{3}{20}\)

e) Ta có: \(\left(8\frac{5}{11}+3\frac{5}{8}\right)-3\frac{5}{11}\)

\(=\frac{93}{11}+\frac{29}{8}-\frac{38}{11}\)

\(=5+\frac{29}{8}=\frac{40}{8}+\frac{29}{8}=\frac{69}{8}\)

f) Ta có: \(\frac{4}{9}:\left(-\frac{1}{7}\right)+6\frac{5}{9}:\left(-\frac{1}{7}\right)\)

\(=\frac{4}{9}\cdot\left(-7\right)+\frac{59}{9}\cdot\left(-7\right)\)

\(=\left(-7\right)\cdot\left(\frac{4}{9}+\frac{59}{9}\right)=\left(-7\right)\cdot7=-49\)

g) Ta có: \(\frac{-1}{4}\cdot13\frac{9}{11}-0,25\cdot6\frac{2}{11}\)

\(=\frac{-1}{4}\cdot\frac{152}{11}+\frac{-1}{4}\cdot\frac{68}{11}\)

\(=\frac{-1}{4}\cdot\left(\frac{152}{11}+\frac{68}{11}\right)=-\frac{1}{4}\cdot20=-5\)

h) Ta có: \(5\frac{27}{5}+\frac{27}{23}+0,5-\frac{5}{27}+\frac{16}{23}\)

\(=\frac{52}{5}+\frac{27}{23}+\frac{1}{2}-\frac{5}{27}+\frac{16}{23}\)

\(=\frac{52}{5}+\frac{43}{23}+\frac{1}{2}-\frac{5}{27}\)

\(=\frac{64584}{6210}+\frac{11610}{6210}+\frac{3105}{6210}-\frac{1150}{6210}\)

\(=\frac{78149}{6210}\)

i) Ta có: \(\frac{3}{8}\cdot27\frac{1}{5}-51\frac{1}{5}\cdot\frac{3}{8}+19\)

\(=\frac{3}{8}\cdot\frac{136}{5}-\frac{3}{8}\cdot\frac{206}{5}+\frac{3}{8}\cdot\frac{152}{3}\)

\(=\frac{3}{8}\cdot\left(\frac{136}{5}-\frac{206}{5}+\frac{152}{3}\right)=\frac{3}{8}\cdot\frac{110}{3}\)

\(=\frac{55}{4}\)

Bình luận (0)

Các câu hỏi tương tự
Phạm Ninh Đan
Xem chi tiết
Phạm Quỳnh Anh
Xem chi tiết
Linh nguyen thuy
Xem chi tiết
Phương Thảo Nguyễn
Xem chi tiết
diiphuong
Xem chi tiết
Phạm Ninh Đan
Xem chi tiết
Nguyễn Duy
Xem chi tiết
Phương Thảo Nguyễn
Xem chi tiết
Linh nguyen thuy
Xem chi tiết