Bài 1 : Tính nhanh
\(\dfrac{-2}{7}\) x \(\dfrac{125}{9}\) : \(\dfrac{3}{14}\): \(^{\left(-5^2\right)}\)
b, \(\dfrac{35}{17}\) +\(\dfrac{2}{13}\) -(\(\dfrac{11}{13}\) + 1\(\dfrac{1}{17}\))
c, \(\dfrac{13}{17}\)+\(\dfrac{23}{37}\) - \(\dfrac{23}{37}\) - \(\dfrac{11}{23}\) + \(\dfrac{2}{23}\)
Bài 2 : Tìm x
a,2x+3 = \(1\dfrac{2}{3}\)
b,0,15 - 3x = \(^{\left(-10^0\right)}\)
c,-x : \(\dfrac{2}{5}\)= 0,8
d,\(\dfrac{3x+2}{3}\) = \(\dfrac{-4}{5}\)
Bài 1:
\(a,\dfrac{-2}{7}.\dfrac{125}{9}:\dfrac{3}{14}:\left(-5^2\right)\)
\(=\dfrac{-2}{7}.\dfrac{125}{9}.\dfrac{14}{3}.\dfrac{1}{25}\)
\(=\dfrac{\left(-2\right).5.2}{9.3}\)
\(=\dfrac{-20}{27}\)
\(b,\dfrac{35}{17}+\dfrac{2}{13}-\left(\dfrac{11}{13}+1\dfrac{1}{17}\right)\)
\(=\dfrac{35}{17}+\dfrac{2}{13}-\dfrac{11}{13}-\dfrac{18}{17}\)
\(=\left(\dfrac{35}{17}-\dfrac{18}{17}\right)+\left(\dfrac{2}{13}-\dfrac{11}{13}\right)\)
\(=\dfrac{17}{17}+\dfrac{-9}{13}\)
\(=1-\dfrac{9}{13}\)
\(=\dfrac{13}{13}-\dfrac{9}{13}\)
\(=\dfrac{4}{13}\)
\(c,\dfrac{13}{17}+\dfrac{23}{37}-\dfrac{23}{37}-\dfrac{11}{23}+\dfrac{2}{23}\)
\(=\left(\dfrac{23}{37}-\dfrac{23}{37}\right)-\left(\dfrac{11}{23}-\dfrac{2}{23}\right)+\dfrac{13}{17}\)
\(=0-\dfrac{9}{23}+\dfrac{13}{17}\)
\(=\dfrac{-153}{391}+\dfrac{299}{391}\)
\(=\dfrac{146}{391}\)
