\(=\left(-\dfrac{25}{13}+\dfrac{12}{13}\right)+\left(-\dfrac{9}{11}\right)+\left(-\dfrac{25}{17}\right)\\ =1-\dfrac{9}{11}-\dfrac{25}{17}=\dfrac{187}{187}-\dfrac{153}{187}-\dfrac{275}{187}=-\dfrac{241}{187}\)
\(=\left(-\dfrac{25}{13}+\dfrac{12}{13}\right)+\left(-\dfrac{9}{11}\right)+\left(-\dfrac{25}{17}\right)\\ =1-\dfrac{9}{11}-\dfrac{25}{17}=\dfrac{187}{187}-\dfrac{153}{187}-\dfrac{275}{187}=-\dfrac{241}{187}\)
Thực hiện phép tính ( tính nhanh nếu có thể ) :
a) \(\dfrac{3}{5}+\dfrac{1}{5}.\dfrac{-17}{9}\)
b) \(\left(-\dfrac{4}{15}-\dfrac{18}{19}\right)-\left(\dfrac{20}{19}+\dfrac{11}{15}\right)\)
Thực hiện phép tính (tính nhanh nếu có thể):
a/ \(\dfrac{3}{5}+\dfrac{1}{5}.\dfrac{-17}{9}\) b/ \(\left(-\dfrac{4}{15}-\dfrac{18}{19}\right)\)-\(\left(\dfrac{20}{19}+\dfrac{11}{15}\right)\)
Tính nhanh
\(c,\dfrac{-5}{13}-\left(\dfrac{3}{5}+\dfrac{3}{13}-\dfrac{4}{10}\right)\)
\(d,\left(\dfrac{1}{9}-\dfrac{9}{17}\right)+\dfrac{3}{6}-\left(\dfrac{12}{17}-\dfrac{1}{2}\right)+\dfrac{5}{9}\)
\(\dfrac{2022}{2023}.\left(\dfrac{9}{13}-\dfrac{7}{11}\right)+\dfrac{2022}{2023}.\left(\dfrac{17}{13}-\dfrac{4}{17}\right)\)
1, Tính hợp lí
\(A=\dfrac{0.5+\dfrac{7}{12}-\dfrac{5}{6}}{1-\dfrac{2}{3}+0,75}\)
\(B=-66.\left(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{11}\right)+124.\left(-37\right)+126.\left(-62\right)\)
\(N=\left(60\dfrac{7}{13}+50\dfrac{8}{13}-11.\dfrac{2}{13}\right)x\) (Với \(x=-2017\dfrac{7}{10}\))
\(M=\left(1-\dfrac{2}{2.3}\right).\left(1-\dfrac{2}{3.4}\right).\left(1-\dfrac{2}{4.5}\right).....\left(1-\dfrac{2}{99.100}\right)\)
hãy tính giá trị của biểu thức sau:
C=\(\left|-3\left(-\dfrac{13}{15}-\dfrac{17}{21}\right)\right|-\left|-\dfrac{13}{5}+\dfrac{17}{7}\right|+\left(-12+\dfrac{35}{3}\right):\left|-\dfrac{7}{6}\right|\)
thực hiện phép tính bằng cách hợp lí nhất:
a)\(\dfrac{5}{3}+\left(\dfrac{-2}{7}\right)-\left(-1,2\right)\) b)\(\dfrac{-4}{9}+\left(\dfrac{-5}{6}\right)-\dfrac{17}{4}\)
Câu 1: Thực hiện phép tính
a, \(40\dfrac{1}{4}:\dfrac{5}{7}-25\dfrac{1}{4}:\dfrac{5}{7}-\dfrac{1}{2021}\)
b, \(\left|\dfrac{-5}{9}\right|.\sqrt{81}-2021^0.\dfrac{16}{25}\)
Câu 2: Tìm x
\(3\left(x-\dfrac{1}{3}\right)-7\left(x+\dfrac{3}{7}\right)=-2x+\dfrac{1}{3}\)
a)\(\left(\dfrac{5}{9}-\dfrac{\sqrt{9}}{12}\right):\dfrac{3}{4}+\dfrac{11}{3}:\dfrac{3}{4}\) b)\(\left(0,\left(3\right)+\dfrac{\text{|}-2\text{|}}{3}\right):\dfrac{\sqrt{25}}{4}-\left(2^3+3^2\right)^0\)
Câu 1: Tìm x, biết:
a)\(x^2-\dfrac{16}{25}=0\) b)\(\dfrac{2}{5}-\left|\dfrac{1}{2}-x\right|=6\)
C2.Tính giá của biểu thức:
a)\(A=1\dfrac{5}{13}-0,25-\left(2\dfrac{5}{9}+\dfrac{18}{13}-\dfrac{1}{4}\right)\)
b)\(\dfrac{\dfrac{3}{5}.7^2-3.5^6+\dfrac{3}{5}.3^9}{\dfrac{3}{4}.7^2-\dfrac{3}{4}.5^7+\dfrac{3}{4}.3^9}\)