\(=5+\dfrac{17}{39}+4+\dfrac{2}{85}-3-\dfrac{2}{45}-13-\dfrac{19}{85}+\dfrac{11}{45}-\dfrac{4}{39}\)
\(=\left(-4\right)+\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}=-4+\dfrac{1}{3}=-\dfrac{11}{3}\)
Bài 1: Tính
\(\dfrac{1}{2}-\left(\dfrac{-16}{17}\right)+\dfrac{4}{5}-\left(\dfrac{-4}{9}\right)+\dfrac{11}{45}+\dfrac{19}{34}+\dfrac{19}{105}\)
BT1: Tính nhanh:
1) \(\dfrac{1}{2}-\left(\dfrac{-16}{17}\right)+\dfrac{4}{5}-\left(\dfrac{-4}{9}\right)-\dfrac{11}{45}+\dfrac{19}{34}+\dfrac{19}{105}\)
\(\dfrac{4}{9}.19\dfrac{1}{3}+\dfrac{-4}{9}.39\dfrac{1}{3}+\dfrac{-3^2}{5}:\left(-0,2\right)\)
\(\dfrac{\left(-5^3\right)^2}{27}.\dfrac{3}{23}.\dfrac{6^2}{-5^6}\)
\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
\(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}:33\dfrac{1}{3}\)
\(\dfrac{3}{4}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\)
x:(-2,14)=(-3,12):1,2
Tính giá trị của biểu thức : \(A=\dfrac{45}{19}-\left\{\dfrac{1}{2}+\left[\dfrac{1}{3}+\left(\dfrac{1}{4}\right)^{-1}\right]^{-1}\right\}^{-1}\)
\(Chobaitoansau:\)
\(M=\dfrac{75-\dfrac{6}{13}+\dfrac{3}{17}-\dfrac{3}{19}}{257-\dfrac{22}{13}+\dfrac{11}{17}-\dfrac{11}{19}}\)
\(2N=\dfrac{1,1+0,19-1,32}{2,06+0,54}-\left(\dfrac{1}{2}+\dfrac{1}{3}\right):2\)
\(P=\left(5\dfrac{7}{8}-2\dfrac{1}{4}-0,5\right):2\dfrac{23}{26}\)
a, Tính M, P
b, Tìm x∈ Z, biết N < x < P
tính
a) \(\left[\dfrac{0.8\div\left(\dfrac{4}{5}\cdot1025\right)}{0.64-1}+\dfrac{\left(1.08-\dfrac{2}{25}\right)\div\dfrac{4}{7}}{\left(6\dfrac{5}{7}-3\dfrac{1}{4}\right)\cdot2\dfrac{2}{17}}+\left(1.2\cdot0.5\right)\div\dfrac{4}{5}\right]\)
b) \(\left(0.2\right)^{-3}\left[\left(-\dfrac{1}{5}\right)^{-2}\right]^{-1}+\left[\left(\dfrac{1}{2}\right)^{-3}\right]^{-2}\div\left(2^{-3}\right)^{-1}-\left(0.175\right)^{-2}\)
c) \(2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{1+\dfrac{1}{2}}}}\)
d) \(\dfrac{1}{90}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{3}\)
e) \(\left(\dfrac{1}{3}\right)^{-1}-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2\div2\)
f) \(\dfrac{\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{13}}{\dfrac{2}{3}-\dfrac{2}{7}-\dfrac{2}{13}}\cdot\dfrac{\dfrac{3}{4}-\dfrac{3}{16}-\dfrac{3}{64}-\dfrac{3}{256}}{1-\dfrac{1}{4}-\dfrac{1}{16}-\dfrac{1}{64}}+\dfrac{5}{8}\)
g) \(\dfrac{1}{-\left(2017\right)\left(-2015\right)}+\dfrac{1}{\left(-2015\right)\left(-2013\right)}+...+\dfrac{1}{\left(-3\right)\cdot\left(-1\right)}\)
h) \(\left(1-\dfrac{1}{1\cdot2}\right)+\left(1-\dfrac{1}{2\cdot3}+...+\left(1-\dfrac{1}{2017\cdot2018}\right)\right)\)
Tính giá trị biểu thức :
A=\(\left[\dfrac{1\dfrac{11}{31}.4\dfrac{3}{7}-\left(15-6\dfrac{1}{3}.\dfrac{2}{19}\right)}{4\dfrac{5}{6}+\dfrac{1}{6}\left(12-5\dfrac{1}{3}\right)}\right].\dfrac{31}{50}\)
Tính giá trị biểu thức
A=\(\dfrac{\left(1+17\right)\cdot\left(1+\dfrac{17}{2}\right)\cdot\left(1+\dfrac{17}{3}\right)....\left(1+\dfrac{17}{19}\right)}{\left(1+19\right)\cdot\left(1+\dfrac{19}{2}\right)\cdot\left(1+\dfrac{19}{3}\right)....\left(1+\dfrac{19}{17}\right)}\)
Tìm x, biết:
a) \(\dfrac{11}{13}-\left(\dfrac{5}{42}-x\right)=-\left(\dfrac{15}{28}-\dfrac{11}{13}\right)\)
b) \(2x.\left(x-\dfrac{1}{7}\right)=0\)
c) \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
