(x-\(\frac{1}{3}\))+\(\frac{4}{5}\)=((-3.2)+\(\frac{2}{5}\))
\(4^x+\frac{1}{3}=\frac{3}{2}\)
\(\frac{1}{3}-\frac{2}{5}+\frac{3}{x}=\frac{3}{4}\)
\(2.\left(\frac{3}{4}-\frac{5}{x}\right)=\frac{4}{5}-3.x\)
\(\frac{3}{2}-4.\left(\frac{1}{4}-x\right)=\frac{2}{3}-\frac{7}{x}\)
\(3.2^x=4^5.16^2\)
Tìm x biết:
\(\left|x-\frac{1}{3}\right|+\frac{4}{5}=\left|\left(-3.2\right)+\frac{2}{5}\right|\)
Khó quá
\(\frac{3!\left(2^x\left(15\%\left(-8\frac{2\frac{2}{5}}{5}+8\frac{3\frac{3}{4}}{5}\right)\right)\right)}{24}=\frac{81}{x^3.2}\)
x = ?
\(x-\frac{1}{3}|\)+\(\frac{4}{5}\)=\(\left(-3.2\right)+\frac{2}{5}|\)
tìm x ?
\(\left|x-\frac{1}{3}\right|+\frac{4}{5}=\left(-3,2\right)+\frac{2}{5}\)
\(\Rightarrow\left|x-\frac{1}{3}\right|+\frac{4}{5}=\frac{-14}{5}\)
\(\Rightarrow\left|x-\frac{1}{3}\right|=\frac{-14}{5}-\frac{4}{5}\)
\(\Rightarrow\left|x-\frac{1}{3}\right|=\frac{-18}{5}\)
Vì giá trị tuyệt đối không thể là một số âm
\(\Rightarrow x\in\varnothing\)
Dấu gạch xuống là trị tuyệt đối hả bạn?
Tìm x:
2x+2 - 3.2x =16
\(\left(\frac{1}{5}-\frac{3}{2}x\right)^2=\frac{9}{4}\)
\(2^{x+2}-3.2^x=16\)
=> \(2^x.2^2-3.2^x=16\)
=> \(2^x.\left(2^2-3\right)=16\)
=> \(2^x.1=2^4\)
=> x = 4
\(\left(\frac{1}{5}-\frac{3}{2}x\right)^2=\frac{9}{4}\)
=> \(\left(\frac{1}{5}-\frac{3}{2}x\right)^2=\left(\frac{3}{2}\right)^2\)
=> \(\orbr{\begin{cases}\frac{1}{5}-\frac{3}{2}x=\frac{3}{2}\\\frac{1}{5}-\frac{3}{2}x=-\frac{3}{2}\end{cases}}\)
=> \(\orbr{\begin{cases}\frac{3}{2}x=\frac{1}{5}-\frac{3}{2}\\\frac{3}{2}x=\frac{1}{5}+\frac{3}{2}\end{cases}}\)
=> \(\orbr{\begin{cases}\frac{3}{2}x=-\frac{13}{10}\\\frac{3}{2}x=\frac{17}{10}\end{cases}}\)
=> \(\orbr{\begin{cases}x=\frac{-13}{15}\\x=\frac{17}{15}\end{cases}}\)
Bài 1 : tìm x, biết
a) \(\left(\frac{1}{4}-x\right)\left(x+\frac{2}{5}\right)=0\)
bài 2 : Thực hiện các phép tính sau bằng cách hợp lí nếu có thể :
a) \(\left(\frac{13}{24}-\frac{29}{30}\right):\left(\frac{-51}{5}\right)\)
bài 3 : tính nhanh
A = \(\frac{1}{3}-\frac{3}{4}-\left(\frac{-3}{5}\right)+\frac{1}{72}-\frac{2}{9}-\frac{1}{36}+\frac{1}{15}\)
B = \(\frac{1}{5}-\frac{3}{7}+\frac{5}{9}-\frac{2}{11}+\frac{7}{13}-\frac{9}{16}-\frac{7}{13}+\frac{2}{11}-\frac{5}{9}+\frac{3}{7}-\frac{1}{5}\)
C = \(\frac{1}{100}-\frac{1}{100.99}-\frac{1}{99.98}-\frac{1}{98.97}-....-\frac{1}{3.2}-\frac{1}{2.1}\)
\(\left(\frac{1}{4}-x\right)\left(x+\frac{2}{5}\right)=0\)
Ta xét 2 trường hợp
\(\begin{cases}\frac{1}{4}-x=0\\x+\frac{2}{5}=0\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{1}{4}\\x=-\frac{2}{5}\end{cases}}\)
tớ mới làm bài 1 thôi bài 2 3 tớ ko có thời gian
Bài 1: Tìm x, biết:
\(\left(\frac{1}{4}-x\right)\left(x+\frac{2}{5}\right)=0\)
\(\Rightarrow\hept{\begin{cases}\frac{1}{4}-x=0\\x+\frac{2}{5}=0\end{cases}\Rightarrow\hept{\begin{cases}x=\frac{1}{4}\\x=-\frac{2}{5}\end{cases}}}\)
Bài 1: Tính nhanh:
\(C=\frac{1}{100}-\frac{1}{100.99}-\frac{1}{99.98}-\frac{1}{98.97}-...-\frac{1}{3.2}-\frac{1}{2.1}\)
Bài 2: Tìm tập hợp số nguyên x, biết rằng:
\(4\frac{5}{9}:2\frac{5}{18}-7< x< \left(3\frac{1}{5}:3,2+4,5.1\frac{31}{45}\right):\left(-21\frac{1}{2}\right)\)
Ặc =)))) Giúp hay không thì tùy =))
\(H=\frac{1}{100}-\frac{1}{100\cdot99}-\frac{1}{99\cdot98}-...-\frac{1}{2\cdot1}\)
\(U=\frac{1}{100}-\left(\frac{1}{100\cdot99}+\frac{1}{99\cdot98}+...+\frac{1}{2\cdot1}\right)\)
\(U=\frac{1}{100}-\left(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+...+\frac{1}{99\cdot100}\right)\)
\(H=\frac{1}{100}-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\right)\)
\(HU=\frac{1}{100}-\left(1-\frac{1}{100}\right)\)
\(UH=\frac{1}{100}-1+\frac{1}{100}\)
\(HU=\frac{2}{100}-1=-\frac{49}{50}\)
\(\frac{3x}{2}-\frac{1}{3}=\frac{2}{5}+x\)
\(x-\frac{11}{15}=\frac{3+x}{5}\)
\(\left(x-4\right).\frac{50}{120}=\frac{40x}{120}+\left(-2\right)^2\)
\(2x-\left(\frac{70x}{140}+\frac{25x}{100}\right)=-5\frac{1}{4}\)
-153 - |x-2|\(^2\) :(-3)\(^3\) =|(-2)^5-8^2|
12x-(3x+6).1/3=|(-5)^3+3.2|
\(\left(8-\frac{9}{4}+\frac{2}{7}\right)-\left(-6-\frac{3}{7}+\frac{5}{4}\right)-\left(3+\frac{2}{4}-\frac{9}{7}\right)\)\(\frac{9}{7}\))
\(\frac{1}{3}-\frac{3}{5}+\frac{5}{7}-\frac{7}{9}+\frac{9}{11}-\frac{11}{13}+\frac{13}{15}+\frac{11}{13}-\frac{9}{11}+\frac{7}{9}-\frac{5}{7}+\frac{3}{5}-\frac{1}{3}\)
\(\frac{1}{2014}-\frac{1}{2014.2013}-\frac{1}{2013.2012}-\frac{1}{2012.2011}-...-\frac{1}{3.2}-\frac{1}{2.1}\)