Question

Thực hiện phép tính

a) (-3/5)^14:(-3/5)^13

b) (-2)^3x(3/4-0,25)(2/1/4-1/1/6)

c) 7/17x5/8-5/8x(-3/17)-5/8x18/17

Answer 1

a) \(\left(-\frac{3}{5}\right)^{14}:\left(-\frac{3}{5}\right)^{13}\)

\(=\left(-\frac{3}{5}\right)^{14-13}\)

\(=\left(-\frac{3}{5}\right)^1\)

\(=-\frac{3}{5}.\)

Chúc bạn học tốt!

Answer 2

a) \(\left(\frac{-3}{5}\right)^{14}:\left(\frac{-3}{5}\right)^{13}=\frac{-3}{5}\)

Answer 3

a)

\(\left(-\frac{3}{5}\right)^{14}-\left(-\frac{3}{5}\right)^{13}\)

\(=\left(-\frac{3}{5}\right)^{14-13}\)

\(=\left(-\frac{3}{5}\right)^1=-\frac{3}{5}\)

b)

\(\left(-2\right)^3\cdot\left(\frac{3}{4}-0,25\right)\left(\frac{2}{\frac{1}{4}}-\frac{1}{\frac{1}{6}}\right)\)

\(=-8\cdot\left(\frac{3}{4}-\frac{1}{4}\right)\cdot\left(\frac{2}{4}-\frac{1}{6}\right)\)

\(=-\frac{8}{1}\cdot\frac{2}{4}\cdot\left(\frac{1}{2}-\frac{1}{6}\right)\)

\(=-\frac{16}{4}\cdot\left(\frac{3}{6}-\frac{1}{6}\right)\)

\(=-\frac{4}{1}\cdot\frac{2}{6}=-\frac{4}{1}\cdot\frac{1}{3}=-\frac{4}{3}\)

c)

\(\frac{7}{17}\cdot\frac{5}{8}-\frac{5}{8}\cdot\left(-\frac{3}{17}\right)-\frac{5}{8}\cdot\frac{18}{17}\)

\(=\frac{5}{8}\cdot\left[\frac{7}{17}-\left(-\frac{3}{17}\right)-\frac{18}{17}\right]\)

\(=\frac{5}{8}\cdot\left[\frac{7}{17}+\frac{3}{17}-\frac{18}{17}\right]\)

\(=\frac{5}{8}\cdot\left[\frac{7+3-18}{17}\right]\)

\(=\frac{5}{8}\cdot\left(-\frac{2}{17}\right)=\frac{5\cdot-2}{8\cdot17}=\frac{-10}{136}=\frac{-5}{68}\)

Answer 4

Mình sửa lại câu c) khúc cuối

\(=\frac{5}{8}\cdot\left(-\frac{8}{17}\right)=\frac{5\cdot\left(-8\right)}{8\cdot17}=\frac{-40}{136}=\frac{-5}{17}\)