B=\(\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^3\)
\(\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^3\)
\(a,18\frac{2}{17}+\frac{15}{23}-1\frac{19}{17}+\frac{3}{19}-\frac{38}{23}\)
\(b,\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(\frac{40}{100}-1,4\right).\left(-2\right)^3\)
Thực hiện phếp tính:
\(A=-\frac{7}{12}+\frac{11}{8}-\frac{5}{9}\)
\(B=5.\left(-2\right)^2-4.\left(-5\right)-20\)
\(C=\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^2\)
A= \(\frac{19}{24}\) - \(\frac{5}{9}\)
A= \(\frac{17}{72}\)
B= 5. (-4) -4.(-5) - 20
B= -20 - (-20) - 20
B= 0 - 20
B= -20
tính
B =\(\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^3\)
ai nhanh tớ tick
trình bày lời giải nha
\(=\left(\frac{5}{7}\cdot0,6-5:3\frac{1}{2}\right)\cdot\left(40\%-1,4\right)\left(-2\right)^3\)
\(=\left(\frac{5}{7}\cdot\frac{3}{5}-5:\frac{7}{2}\right)\left(\frac{2}{5}-\frac{1}{4}\right)\cdot\left(-8\right)\)
\(=\left(\frac{25}{21}-\frac{10}{7}\right)\cdot\frac{3}{20}\cdot\left(-8\right)\)
\(=-\frac{5}{21}\cdot\frac{3}{20}\cdot\left(-8\right)\)
\(=-\frac{2}{7}\)
Nhớ k nha các bạn gái làm vợ đi
\(B=\left(\frac{3}{7}-5:\frac{7}{2}\right).\left(\frac{2}{5}-1,4\right).\left(-8\right)\)
\(B=\left(\frac{3}{7}-\frac{35}{2}\right).\left(-1\right).\left(-8\right)\)
\(B=-\frac{239}{14}.\left(-1\right).\left(-8\right)\)
\(B=-\frac{956}{7}\)
Ps: Không làm quá chi tiết vì mất thời gian. Mà làm vậy là quá chi tiết so với bình thường tui làm rồi!
Bài 1: Thực hiện phép tính sau:
1) \(A=\dfrac{-2}{4}+\dfrac{2}{7}-\dfrac{5}{28}\)
2) \(B=\left(\dfrac{5}{7}.0,6-5:3\dfrac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^3\)
GPT :
a, \(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2011}+\frac{1}{2012}..\right).503x=1+\frac{2014}{2}+\frac{2015}{3}+...+\frac{4023}{2011}+\frac{4024}{2012}\)
b, \(\left(\frac{0,6+\frac{3}{7}-\frac{2}{11}}{1+\frac{5}{7}-\frac{5}{11}}+\frac{\frac{2}{3}-1,5+\frac{2}{9}}{\frac{5}{3}-3,75+\frac{5}{9}}\right)+93x=\left(\frac{3737}{4545}-\frac{954954}{975975}\right).\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)-7.\left(x-3\right)\)
\(VP=1+\frac{2014}{2}+\frac{2015}{3}+...+\frac{4023}{2011}+\frac{4024}{2012}\)
\(=1-1+\left(\frac{2014}{2}-1\right)+\left(\frac{2015}{3}-1\right)+...+\left(\frac{4023}{2011}-1\right)+\left(\frac{40024}{2012}-1\right)+2012\)
\(=\frac{2012}{2}+\frac{2012}{3}+...+\frac{2012}{2011}+\frac{2012}{2012}+\frac{2012}{1}\)
\(=2012.\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2011}+\frac{1}{2012}\right)\)
\(\Rightarrow2012=503.x\Rightarrow x=\frac{2012}{503}=4\)
GPT :
a, \(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2011}+\frac{1}{2012}..\right).503x=1+\frac{2014}{2}+\frac{2015}{3}+...+\frac{4023}{2011}+\frac{4024}{2012}\)
b, \(\left(\frac{0,6+\frac{3}{7}-\frac{2}{11}}{1+\frac{5}{7}-\frac{5}{11}}+\frac{\frac{2}{3}-1,5+\frac{2}{9}}{\frac{5}{3}-3,75+\frac{5}{9}}\right)+93x=\left(\frac{3737}{4545}-\frac{954954}{975975}\right).\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)-7.\left(x-3\right)\)
\(\left[5\frac{1}{6}-\left(0,6:7\frac{1}{2}+3\frac{2}{5}.0,35\right)\right]:\left(12-2\frac{2}{3}.4\frac{3}{4}\right)\)
Tính nhanh
Bài 1:
1. Tính: \(E=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{200}\left(1+2+...+200\right)\)
2. Tìm và tính tổng các số nguyên x thỏa mãn: \(\frac{21}{5}\left|x\right|< 2019\)
3. Tìm x, biết: \(\frac{2^{24}\left(x-3\right)}{\left(3\frac{5}{7}-1,4\right)\left(6\cdot2^{24}-4^{13}\right)}=\left(\frac{5}{3}\right)^2\)
\(1+2+...+n=\frac{n\left(n+1\right)}{2}\)
\(\Rightarrow E=1+\frac{1}{2}\frac{2.3}{2}+\frac{1}{3}.\frac{3.4}{2}+\frac{1}{4}.\frac{4.5}{2}+...+\frac{1}{200}.\frac{200.201}{2}\)
\(=1+\frac{1}{2}\left(3+4+5+...+201\right)\)
\(=1+\frac{1}{2}\left(1+2+3+...+201-1-2\right)\)
\(=1+\frac{1}{2}\left(\frac{201.202}{2}-3\right)=10150\)
\(\frac{21}{5}\left|x\right|< 2019\Rightarrow\left|x\right|< 2019\div\frac{21}{5}=\frac{3365}{7}\)
\(\Rightarrow-480\le x\le480\)
\(\Rightarrow\sum x=-480+480-479+479+...+-1+1+0=0\)
\(\frac{2^{24}\left(x-3\right)}{\frac{81}{35}.\left(6.2^{24}-2^{26}\right)}=\frac{25}{9}\)
\(\Leftrightarrow\frac{2^{24}\left(x-3\right)}{2^{24}\left(6-2^2\right)}=\frac{25}{9}.\frac{81}{35}\)
\(\Leftrightarrow\frac{x-3}{2}=\frac{45}{7}\)
\(\Leftrightarrow x-3=\frac{90}{7}\)
\(\Rightarrow x=\frac{111}{7}\)