TÌM X :
\(\frac{2}{9}x\left(x-3\frac{7}{8}\right)=0\)
Tìm x biết
a) (8-5x).(x+2)+4.(x-2).(x+1)+2.(x-2).(x+2)=0
b)\(\left(-\frac{2}{5}+x\right):\frac{7}{9}+\left(-\frac{3}{5}+\frac{5}{6}\right):\frac{7}{9}=0\)
c)\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=1\frac{2003}{2004}\)
Tìm x, biết:
a)\(\left(x+5\right).\left(x+9\right)>0\)
b)\(\left(\frac{1}{7}x-\frac{2}{7}\right).\left(-\frac{1}{5}x+\frac{3}{5}\right).\left(\frac{1}{3}x+\frac{4}{3}\right)=0\)
bạn ơi trả lời được câu này kông
( x + 1 ) + ( x - 3 ) + ( x + 5 ) + ............ + ( x +9) = 35
\(3,2.\frac{15}{16}-\left(75\%+\frac{2}{7}\right):\left(-1\frac{1}{28}\right)\)
\(\left(0,25+12,5-\frac{5}{16}\right):\left[12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right]\)
\(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)
\(14,5-\frac{8}{9}:\left(35-34\frac{8}{9}\right).\frac{9}{8}\)
\(1\frac{1}{15}-\left(\frac{1}{15}+\frac{4}{9}:\frac{-2}{3}-\frac{28}{16}.\frac{6}{35}\right)-\frac{3}{10}\)
Tìm x
\(\left(4,5-2x\right)\left(-3\frac{2}{3}\right)=\frac{11}{15}\)
\(\backslash34-x\backslash=\left(-3\right)^4\)
\(\left(4x^2-1\right)\left(\text{\x}\backslash-\frac{2}{3}\right)=0\)
\(\frac{3}{5}x-\frac{1}{2}\)\(x=\frac{-7}{20}\)
\(=\frac{16}{5}.\frac{15}{16}-\left(\frac{3}{4}+\frac{2}{7}\right):\left(\frac{-29}{28}\right)\)
\(=3-\left(\frac{21}{28}+\frac{8}{28}\right):\left(\frac{-29}{28}\right)\)
\(=3-\left(\frac{29}{28}\right).\left(\frac{-28}{29}\right)\)
\(=3-\left(-1\right)\)
\(=4\)
b) \(=\left(\frac{1}{4}+\frac{25}{2}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right)\)
\(=\left(\frac{4}{16}+\frac{200}{16}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3.3}{2.3.4}-\frac{2}{2.3.4}\right)\right)\)
\(=\left(\frac{199}{16}\right):\left(12-\frac{7}{12}:\left(\frac{9}{24}-\frac{2}{24}\right)\right)\)
\(=\frac{199}{16}:\left(12-\frac{7}{12}.\frac{24}{7}\right)\)
\(=\frac{199}{16}:\left(12-2\right)\)
\(=\frac{199}{16}:10\)
\(=\frac{199}{160}\)
c) \(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)
\(\left(\frac{-33}{55}+\frac{25}{55}\right):\frac{-3}{7}+\left(\frac{4}{5}\right):\frac{-3}{7}\)
\(\left(\frac{-8}{55}\right).\frac{-7}{3}+\frac{4}{5}.\frac{-7}{3}\)
\(\frac{-7}{3}\left(\frac{-8}{55}+\frac{4}{5}\right)\)
\(\frac{-7}{3}.\frac{36}{55}=\frac{-84}{55}\)
nhớ làm giúp mình nhá mai mình phải đi học r :<
tìm x
|x+1|+|x-1|=2x-3
tìm x,y,z
\(\left|xy+\frac{2}{3}\right|+\left|yz-\frac{8}{9}\right|+\left|zx+\frac{3}{4}\right|=0\)
tìm x:
a,\(\left(x-\frac{7}{9}\right)^3=\left(\frac{2}{3}\right)^6\)
b,\(\left(\frac{x}{2}-5\right)^5=-32\)
c,\(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+11}=0\)
a,\(\left(x-\frac{7}{9}\right)^3=\left(\left(\frac{2}{3}\right)^2\right)^3\)
\(x-\frac{7}{9}=\frac{4}{9}\)
\(x=\frac{4}{9}+\frac{7}{9}\)
\(x=\frac{11}{9}\)
Vậy x=\(\frac{11}{9}\)
Tính
\(\frac{1}{9}\): \(\frac{8}{27}\):\(\frac{-1}{3}\)
\(\left(\frac{-3}{4}+\frac{2}{5}\right)\):\(\frac{3}{7}\)+\(\left(\frac{3}{5}+\frac{-1}{4}\right)\):\(\frac{3}{7}\)
\(\frac{7}{8}\):\(\left(\frac{2}{9}-\frac{1}{18}\right)+\frac{7}{8}:\left(\frac{1}{36}-\frac{5}{12}\right)\)
Tìm x thuộc Q bt
\(\left(3x+5\right).\left(2x-4\right)=0\)
\(\left(x^2-1\right).\left(x+3\right)=0\)
\(5x^2-\frac{1}{2}x=0\)
\(\frac{x}{4}-\frac{1}{2}=\frac{3}{4}\)
\(\frac{1}{8}+\frac{7}{8}:x=\frac{3}{4}\)
Tính nhanh
\(A=\frac{99}{100}-\frac{1}{99.100}-\frac{1}{98.99}-.....-\frac{1}{3.2}-\frac{1}{2.1}\)
Giúp mk vs mn ơi
\(A=\frac{99}{100}-\left(\frac{1}{1.2}+\frac{1}{2.3}+..+\frac{1}{99.100}\right)\)
\(A=\frac{99}{100}-\left(1-\frac{1}{100}\right)\)
\(A=\frac{99}{100}-\frac{99}{100}\)
\(A=\frac{99-99}{100}=0\)
Bài 2
\(\left(3x+5\right).\left(2x-4\right)=0\)
\(TH1:3x+5=0\)
\(3x=-5\)
\(x=-\frac{5}{3}\)
\(TH2:2x-4=0\)
\(2x=4\)
\(x=2\)
\(\left(x^2-1\right).\left(x+3\right)=0\)
\(\Rightarrow x^2-1=0\)
\(x^2=1\)
\(\Rightarrow x=1\)
\(x+3=0\)
\(x=-3\)
\(5x^2-\frac{1}{2}x=0\)
\(\Rightarrow5x^2-\frac{x}{2}=0\)
\(\Rightarrow5x^2=\frac{5x^2}{1}=\frac{5x^2.2}{2}\)
\(10x^2-x=x.\left(10x-1\right)\)
\(\frac{x.\left(10x-1\right)}{2}=0\)
\(\frac{x.\left(10x-1\right)}{2}.2=0.2\)
\(10x-1=0\)
\(x=\frac{1}{10}=0.100\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{1}{10}=0.100\\x=0\end{cases}}\)
\(\frac{x}{4}-\frac{1}{2}=\frac{3}{4}\)
\(\frac{x}{4}=\frac{3}{4}+\frac{1}{2}\)
\(\frac{x}{4}=\frac{5}{4}\)
\(\Rightarrow x=5\)
\(\frac{1}{8}+\frac{7}{8}:x=\frac{3}{4}\)
\(\frac{7}{8}:x=\frac{3}{4}-\frac{1}{8}\)
\(x=\frac{7}{8}:\frac{5}{8}\)
\(x=\frac{56}{40}=\frac{28}{20}=\frac{14}{10}=\frac{7}{5}\)
\(A=\frac{99}{100}-\left(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\right)\)
\(A=\frac{99}{100}-\left(\frac{1}{1}-\frac{1}{100}\right)\)
\(=\frac{99}{100}-\frac{99}{100}\)
\(=0\)
Tìm x biết:
a)\(\frac{2}{3}.\left(x-\frac{3}{8}\right)-x-\left(-\frac{7}{8}+\frac{2}{3}\right)=\left(\frac{-3}{4}\right)^3:1\frac{11}{16}\)
b)\(-\frac{7}{8}+\frac{7}{8}:\left(\frac{2}{3}-x\right)+\frac{5}{6}:\left(-1\frac{11}{35}\right)=\left(0,8\right)^2\)
Giải hệ phương trình : \(\hept{\begin{cases}\left(x+y\right)^4+3=4\left(x+y\right)\\\frac{x^4-y^4}{64}+\frac{9\left(x^2-y^2\right)}{32}+\frac{7\left(x-y\right)}{8}+3In\left(\frac{x-3}{y-3}\right)=0\end{cases}}\)
3In
a)\(x+\left(x+1\right)+\left(x+3\right)+...+\left(x+2003\right)=2004\)
b)
\(\left(x+2\right)^2=\frac{1}{2}-\frac{1}{3}\)
c)\(\left(2x+1\right)^2=25\)
d)\(\frac{x-6}{7}+\frac{x-7}{8}+\frac{x-8}{9}=\frac{x-9}{10}+\frac{x-10}{11}+\frac{x-11}{12}\)
TÌM X BiẾT:
Làm 1Cau giúp mình cũng đuoc
Câu A
X + (X+1) + (X+3) +...+ (X+2003) = 2004
Số số hạng trong tổng 1 + 3 + ... + 2003 là
(2003 - 1) : 2 + 1 = 1002
Tổng dãy 1 + 3 + ... + 2003 là:
(1 + 2003) * 1002 : 2 = 1004004
=> (1003.X) + 1004004 = 2004
=> (1003.X)= 2004 - 1004004
=> 1003.X = - 1002000
X = - 1002000/1003
E chỉ giải đc đến đây thui!!!!!!!!!!!!!!! :)))
x + ( x + 1) + (x + 3) ... + (x + 2003) = 2004
x + x + x + ... + x (có 1003 x) + 1 + 3 + 5 + ... + 2003 = 2004
x . 1003 + 1004004 = 2004
x . 1003 = 2004 - 1004004
x . 1003 = -1002000
x = -1002000 : 1003
x = -999,00299 = ~-999
a,Khai triển biểu thức ra ta được:
1003x+1004004=2004\(\Leftrightarrow\)1003x=-1002000\(\Leftrightarrow\)x=\(\frac{-1002000}{1003}\)
b,\(\left(x+2\right)^2=\frac{1}{6}\Leftrightarrow\orbr{\begin{cases}x+2=\frac{1}{\sqrt{6}}\\x+2=-\frac{1}{\sqrt{6}}\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{\sqrt{6}}-2\\x=-\frac{1}{\sqrt{6}}-2\end{cases}}}\)
c,\(\left(2x+1\right)^2=25\Leftrightarrow\orbr{\begin{cases}2x+1=5\\2x+1=-5\end{cases}\Leftrightarrow\orbr{\begin{cases}x=2\\x=-3\end{cases}}}\)
d,Cộng 3 vào 2 vế ta có:
\(\frac{x-6}{7}+1+\frac{x-7}{8}+1+\frac{x-8}{9}+1=\frac{x-9}{10}+1+\frac{x-10}{11}+1+\frac{x-11}{12}+1\)
\(\Leftrightarrow\frac{x+1}{7}+\frac{x+1}{8}+\frac{x+1}{9}=\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}\)
\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{7}+\frac{1}{8}+\frac{1}{9}-\frac{1}{10}-\frac{1}{11}-\frac{1}{12}\right)=0\)
Vì \(\hept{\begin{cases}\frac{1}{7}>\frac{1}{10}\\\frac{1}{8}>\frac{1}{11}\\\frac{1}{9}>\frac{1}{12}\end{cases}\Rightarrow\frac{1}{7}+\frac{1}{8}+\frac{1}{9}-\frac{1}{10}-\frac{1}{11}-\frac{1}{12}>0\Rightarrow x+1=0\Leftrightarrow x=-1}\)