Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(A=\frac{4,25\left(x+41,53\right)-125}{\left(3,45+6,55\right):0,1}=\frac{\frac{17}{4}x.+4,25.41,53-125}{10:0,1}\)
\(A=\frac{\frac{17}{4}x+\frac{20601}{400}}{100}\)
Khi x = 58,47
\(A=\frac{\frac{17}{4}.56,47+\frac{20601}{400}}{100}=\frac{588}{200}=2,915\)
b) Với A = 0,535
\(A=\frac{\frac{17}{4}x+\frac{20601}{400}}{100}=0,535\)
\(\frac{17}{4}x=\frac{107}{2}-\frac{20601}{400}=\frac{799}{400}\)
=> x = \(\frac{47}{100}=0,47\)
A = (3,1 – 2,5) – (-2,5 + 3,1) = 3,1 – 2,5 + 2,5 – 3,1 = 0
B = (5,3 – 2,8) – (4 + 5,3) = 5,3 – 2,8 – 4 – 5,3
A=(3,1-2,5)-(-2,5+3,1)=3,1-2,5+2,5-3,1=0
B=(5,3-2,8)-(4+5,3)=5,3-2,8-4-5,3=-6,8
\(\begin{array}{l}\left( {\frac{{20}}{7}.\frac{{ - 4}}{{ - 5}}} \right) + \left( {\frac{{20}}{7}.\frac{3}{{ - 5}}} \right) = \frac{{20}}{7}.\left( {\frac{{ - 4}}{{ - 5}} + \frac{3}{{ - 5}}} \right)\\ = \frac{{20}}{7}.\left( {\frac{{ - 1}}{{ - 5}}} \right) = \frac{{20}}{7}.\frac{1}{5} = \frac{{20}}{{35}} = \frac{4}{7}\end{array}\)
B = \(\left(-1\dfrac{1}{6}\right)\) : \(\left(\dfrac{-10}{3}+\dfrac{9}{4}\right)\) - \(\left(-\dfrac{3}{8}\right)\) : \(\left(8-\dfrac{51}{8}\right)\)
B = \(\dfrac{-7}{6}\) : \(\dfrac{-13}{12}\) - \(\left(-\dfrac{3}{8}\right)\) : \(\dfrac{13}{8}\)
B = \(\dfrac{14}{13}\) - \(\dfrac{-3}{13}\)
B = \(\dfrac{17}{13}\)
Vì số mũ lẻ
=> (-1). (-1)2. (-1)3. (-1)4.... (-1)2011= -1
\(D=\left(1+\dfrac{1}{1.3}\right).\left(1+\dfrac{1}{2.4}\right)...\left(1+\dfrac{1}{2019.2021}\right)=\dfrac{4}{1.3}.\dfrac{9}{2.4}...\dfrac{2019.2021+1}{2019.2021}=\dfrac{2.2}{1.3}.\dfrac{3.3}{2.4}...\dfrac{2020.2020}{2019.2021}=\left(\dfrac{2}{1}.\dfrac{3}{2}...\dfrac{2020}{2019}\right).\left(\dfrac{2}{3}.\dfrac{3}{4}...\dfrac{2020}{2021}\right)=2020.\dfrac{2}{2021}=\dfrac{4040}{2021}\)
\(\begin{array}{l}21.0,1 - \left[ {4 - \left( { - 3,2 - 4,8} \right)} \right]:0,1\\ = 2,1 - \left[ {4 - \left( { - 8} \right)} \right]:0,1\\ = 2,1 - \left[ {4 + 8} \right]:0,1\\ = 2,1 - 12:0,1\\ = 2,1 - 12.10\\ = 2,1 - 120\\ = - \left( {120 - 2,1} \right)\\ = - 117,9\end{array}\)