Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
x+1/3-4=-1
=>x+1/3=-1+4
=>x+1/3=3
=>x =3-1/3
=>x =8/3
Vậy x = 8/3
(2/25-1,008):4/7:(13/4-6/5/9)*36/17
=(2/25-126/125).7/4:(13/4-59/9)*36/17
=(10/125-126/125).7/4:(117/36-236/36)*36/17
=-116/125.7/4.(-36/119).36/17
=-203/125.(-1296/2023)=263088/252875
Mình tính ko nhanh đâu
a) \(\left(\frac{5}{25}-1,008\right):\frac{4}{7}:\left[\left(3\frac{1}{4}-6\frac{5}{9}\right)\cdot2\frac{2}{17}\right]\)
\(=\left(\frac{1}{5}-\frac{126}{125}\right):\frac{4}{7}:\left[\left(\frac{13}{4}-\frac{59}{9}\right)\cdot\frac{36}{17}\right]\)
\(=\left(\frac{25}{125}-\frac{126}{125}\right):\frac{4}{7}:\left[-\frac{119}{36}\cdot\frac{36}{17}\right]\)
\(=-\frac{101}{125}:\frac{4}{7}:\left(-7\right)=-\frac{101}{125}\cdot\frac{7}{4}\cdot\left(-\frac{1}{7}\right)=\frac{101}{500}\)
b) \(\left(-0,5-\frac{3}{5}\right):\left(-3\right)+\frac{1}{3}-\left(-\frac{1}{6}\right):\left(-2\right)\)
\(=\left(-\frac{1}{2}-\frac{3}{5}\right):\left(-3\right)+\frac{1}{3}-\left(-\frac{1}{6}\right)\cdot\left(-\frac{1}{2}\right)\)
\(=-\frac{11}{10}:\left(-3\right)+\frac{1}{3}-\frac{1}{12}\)
\(=\frac{11}{30}+\frac{1}{3}-\frac{1}{12}=\frac{37}{60}\)
\(S=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+......+\frac{1}{2011}-\frac{1}{2012}+\frac{1}{2013}\)
\(=\left(1+\frac{1}{3}+......+\frac{1}{2013}\right)-\left(\frac{1}{2}+\frac{1}{4}+.....+\frac{1}{2012}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+.....+\frac{1}{2013}\right)-\left(\frac{1}{2}+\frac{1}{4}+....+\frac{1}{2012}\right)-\left(\frac{1}{2}+\frac{1}{4}+....+\frac{1}{2012}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+.....+\frac{1}{2013}\right)-2\left(\frac{1}{2}+\frac{1}{4}+.......+\frac{1}{2012}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+.....+\frac{1}{2013}\right)-\left(1+\frac{1}{2}+........+\frac{1}{1006}\right)\)
\(=\frac{1}{1007}+\frac{1}{1008}+......+\frac{1}{2013}\)
\(=P\)
\(\Leftrightarrow S-P=0\)
\(\Leftrightarrow\left(S-P\right)^{2013}=0\)
a) (4/9 + 1/3)^2
= (4/9 + 3/9)^2
= (7/9)^2
= 49/81
b) (1/2 - 3/5)^3
= (5/10 - 6/10)^3
= (-1/10)^3
= -1/1000
c) (-10/3)^5 x (-6/5)^4
= tương tự những câu trên
d) cũng tương tự nhé
Ta có : \(\left(\frac{1}{49}-\frac{1}{2^2}\right)\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right).......\left(\frac{1}{49}-\frac{1}{40^2}\right)\)
\(=\left(\frac{1}{49}-\frac{1}{2^2}\right)\left(\frac{1}{49}-\frac{1}{3^2}\right)......\left(\frac{1}{49}-\frac{1}{7^2}\right)......\left(\frac{1}{49}-\frac{1}{40^2}\right)\)
\(=\left(\frac{1}{49}-\frac{1}{2^2}\right)\left(\frac{1}{49}-\frac{1}{3^2}\right)......0......\left(\frac{1}{49}-\frac{1}{40^2}\right)\)
\(=0\)
\(\frac{7}{8}.(\frac{2}{12}+\frac{4}{10})\)
\(\Rightarrow\frac{7}{8}.(\frac{10+24}{60})\)
\(\Rightarrow\frac{7}{8}.\frac{34}{60}=\frac{238}{480}\)
bt2
\(2.x-\frac{5}{4}=\frac{20}{15}\)
\(\Leftrightarrow2x=\frac{20}{15}+\frac{5}{4}\)
\(\Leftrightarrow2x=\frac{80+75}{60}\)
\(\Leftrightarrow2x=2,5\)
\(\Leftrightarrow x=1,25\)
.7/8.(1/6+2/5)=7/8.17/30=119/240
3/2-5/6:1/4+\(\sqrt{4}\)=3/2-10/3+2=1/6
2x=20/15+5/4
2x=31/12
x=31/12:2
x=31/24
ko bt nha thông cảm
\(2-\frac{2}{3+\frac{1}{2}}=2-\frac{2}{\frac{6}{2}+\frac{1}{2}}=2-\frac{2}{\frac{7}{2}}=2-2:\frac{7}{2}=2-\frac{4}{7}=\frac{10}{7}\)
\(\frac{1-\frac{1}{\frac{3}{4}+1}}{3}=1-\frac{1}{\frac{7}{\frac{4}{3}}}=1-\frac{1}{7}:\frac{4}{3}=1-\frac{3}{28}=\frac{25}{28}\)