Tìm x biết \(\frac{x}{25}\)+\(\frac{x}{40}\)=\(\frac{11}{5}\)
tìm x ,biết:
a)\(\frac{2}{\left(x+2\right)\left(x+4\right)}+\frac{4}{\left(x+4\right)\left(x+8\right)}+\frac{6}{\left(x+8\right)\left(x+14\right)}=\frac{x}{\left(x+2\right)\left(x+14\right)}\)
b)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
c)(x-2)2=\(\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-...+\frac{197}{4851}-\frac{199}{4950}\)
giúp mk với ,huhu
b. (x+1)(1/10+1/11+1/12-1/13-1/14)=0
x+1=0 (vì : 1/10+1/11+1/12-1/13-1/14>0)
x=-1
tìm x ,biết:
a)\(\frac{2}{\left(x+2\right).\left(x+4\right)}+\frac{4}{\left(x+4\right).\left(x+8\right)}+\frac{6}{\left(x+8\right).\left(x+14\right)}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
b)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
c)\(\left(x-2\right)^2=\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-..+\frac{197}{1851}-\frac{199}{1950}\)
giúp mk vs, hu hu
a) \(\frac{2}{\left(x+2\right).\left(x+4\right)}+\frac{4}{\left(x+4\right).\left(x+8\right)}+\frac{6}{\left(x+8\right).\left(x+14\right)}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow\frac{1}{x+2}-\frac{1}{x+4}+\frac{1}{x+4}-\frac{1}{x+8}+\frac{1}{x+8}-\frac{1}{x+14}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow\frac{1}{x+2}-\frac{1}{x+14}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow\frac{x+14}{\left(x+2\right).\left(x+14\right)}-\frac{x+2}{\left(x+2\right).\left(x+14\right)}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow\frac{x+14-x+2}{\left(x+2\right).\left(x+14\right)}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow\frac{16}{\left(x+2\right).\left(x+4\right)}=\frac{x}{\left(x+2\right).\left(x+14\right)}\)
\(\Rightarrow x=16\)
Vậy x = 16
\(b,\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
\(\Leftrightarrow\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}-\frac{x+1}{13}-\frac{x+1}{14}=0\)
\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)
\(\Leftrightarrow x+1=0\left(vì\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\ne0\right)\)
\(\Leftrightarrow x=-1\)
\(\text{Vậy }x=-1\)
Tìm x, biết
a,/\(\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
b,\(^{x^2+\frac{-9}{25}=\frac{2}{5}.\frac{8}{5}}\)
khó quá giúp mk với:))
a/\(\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(\Rightarrow1-x^2=\frac{7}{16}\)
\(\Rightarrow x^2=\frac{9}{16}\)
\(\Rightarrow x=\orbr{\begin{cases}\frac{3}{4}\\-\frac{3}{4}\end{cases}}\)
\(a,\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(1-x^2=\frac{7}{16}\)
\(x^2=1-\frac{7}{16}=\frac{9}{16}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{3}{4}\\x=-\frac{3}{4}\end{cases}}\)
\(b,x^2+-\frac{9}{25}=\frac{2}{5}.\frac{8}{5}\)
\(x^2+-\frac{9}{25}=\frac{16}{25}\)
\(x^2=\frac{16}{25}--\frac{9}{25}=1\)
\(\Rightarrow\orbr{\begin{cases}x=1\\x=-1\end{cases}}\)
học tốt ~~~
a/ \(\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(\Rightarrow\)\(1-x^2=\frac{7}{16}\)
\(\Rightarrow\)\(x^2=1-\frac{7}{16}\)
\(\Rightarrow\)\(x^2=\frac{9}{16}\)
\(\Rightarrow\)\(x^2=\left(\frac{3}{4}\right)^2\)
\(\Rightarrow\)\(x=\frac{3}{4}\)
b, \(x^2+\frac{-9}{25}=\frac{2}{5}.\frac{8}{5}\)
\(\Rightarrow x^2+\frac{-9}{25}=\frac{16}{25}\)
\(\Rightarrow x^2=\frac{16}{25}-\frac{-9}{25}\)
\(\Rightarrow x^2=\frac{25}{25}\)
\(\Rightarrow x^2=\left(\frac{5}{5}\right)^2=\left(\frac{-5}{5}\right)^2\)
\(\Rightarrow x=\frac{5}{5}=\frac{-5}{5}\)
\(\Rightarrow x=1=-1\)
\(\Rightarrow x=\pm1\)
Tìm x , biết : \(\frac{25-x}{995}+\frac{21-x}{997}+\frac{17-x}{999}=\frac{11-x}{334}\)
\(\frac{25-x}{995}+\frac{21-x}{997}+\frac{17-x}{999}=\frac{11-x}{334}\)
\(\Rightarrow\frac{25-x}{995}+2+\frac{21-x}{997}+\frac{17-x}{999}+2=\frac{11-x}{334}+6\)
\(\Rightarrow\frac{25-x}{995}+\frac{1990}{995}+\frac{21-x}{997}+\frac{1994}{997}+\frac{17-x}{999}+\frac{1998}{999}=\frac{11-x}{334}+\frac{2004}{334}\)
\(\Rightarrow\frac{2015-x}{995}+\frac{2015-x}{997}+\frac{2015-x}{999}=\frac{2015-x}{334}\)
\(\Rightarrow\frac{2015-x}{995}+\frac{2015-x}{997}+\frac{2015-x}{999}-\frac{2015-x}{334}=0\)
\(\Rightarrow\left(2015-x\right)\left(\frac{1}{995}+\frac{1}{997}+\frac{1}{999}+\frac{1}{334}\right)=0\)
\(\Rightarrow2015-x=0\left(\text{vì }\frac{1}{995}+\frac{1}{997}+\frac{1}{999}+\frac{1}{334}\ne0\right)\)
\(\Rightarrow x=2015\)
Tìm x biết :
a) \(\frac{x+11}{10}+\frac{x+21}{20}+\frac{x+31}{30}=\frac{x+41}{40}+\frac{x+101}{50}\)
b) \(\frac{x+2}{42}+\frac{x+4}{22}=\frac{x+5}{23}+\frac{x+3}{43}\)
c) \(\frac{x-10}{20}+\frac{x-20}{10}+\frac{x-30}{5}=\frac{x-14}{4}\)
a ) Ta có : \(\frac{x+11}{10}+\frac{x+21}{20}+\frac{x+31}{30}=\frac{x+41}{40}+\frac{x+101}{5}\)
\(\Leftrightarrow\left(\frac{x+11}{10}-1\right)+\left(\frac{x+21}{10}-1\right)+\left(\frac{x+31}{30}-1\right)=\left(\frac{x+41}{40}-1\right)+\left(\frac{x+101}{50}-2\right)\)
\(\Leftrightarrow\frac{x+1}{10}+\frac{x+1}{20}+\frac{x+1}{30}=\frac{x+1}{40}+\frac{x+1}{50}\)
\(\Rightarrow\frac{x+1}{10}+\frac{x+1}{20}+\frac{x+1}{30}-\frac{x+1}{40}-\frac{x+1}{50}=0\)
\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{20}+\frac{1}{30}-\frac{1}{40}-\frac{1}{50}\right)=0\)
Mà \(\left(\frac{1}{10}+\frac{1}{20}+\frac{1}{30}-\frac{1}{40}-\frac{1}{50}\right)\ne0\)
Nên x + 1 = 0
=> x = -1
b) Sai đề à bạn đề \(\frac{x+2}{42}+\frac{x+4}{22}=\frac{x+5}{23}+\frac{x+3}{43}\) hả đề này mk làm đc
Tìm x
a)\(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)
b)\(\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\)
Tìm x biết
a, \(x=\frac{7}{25}+\frac{-1}{5}\)
b, \(x=\frac{5}{11}+\frac{4}{-9}\)
c, \(\frac{5}{9}+\frac{x}{-1}=\frac{-1}{3}\)
a) \(x=\frac{7}{25}+\frac{-1}{5}=\frac{7}{25}+\frac{-5}{25}=\frac{2}{25}\)
b) \(x=\frac{5}{11}+\frac{4}{-9}=\frac{45}{99}+\frac{-44}{99}=\frac{1}{99}\)
c) \(\frac{5}{9}+\frac{x}{-1}=\frac{-1}{3}\)
\(\Rightarrow\frac{x}{-1}=\frac{-1}{3}-\frac{5}{9}\)
\(\Rightarrow\frac{x}{-1}=\frac{-8}{9}\)
\(\Rightarrow x=\frac{\left(-8\right).\left(-1\right)}{9}=\frac{8}{9}\)
TÌM X BIẾT
a) \(\frac{12+x}{42}=\frac{5}{6}\)
b) \(\frac{25-x}{40}=\frac{3}{8}\)
a) 42 x 5 : 6 - 12 = 23
b) 25- 40 x 3 : 8 = 10
Bài 1 : Rút gọn : a)\(K=\frac{2^{11}.9^2}{3^5.16^2}\) b)\(N=\frac{9^3.27^2}{6^2.3^{10}}\) c)\(P=\frac{27^{15}.5^3.8^4}{25^2.81^{11}.2^{11}}\)
Bài 2 : Tìm x,y,z, biết : a) \(\frac{x}{y}=\frac{6}{9}\) và x - y = 30 b)\(\frac{x}{5}=\frac{y}{4}=\frac{z}{7}\) và x + 2y + z =40 c)\(\frac{x}{3}=\frac{y}{4}\); \(\frac{z}{5}=\frac{y}{7}\) và 2x + 3y - z = 106
Bài 3 : Tìm x,y, biết : a) \(\frac{x}{18}=\frac{y}{15}\) và x - y = -30 b) 7x =9y và 10x - 8y =68 c)\(\left(x-\frac{1}{2}\right)^{50}+\left(y+\frac{1}{3}\right)^{40}=0\)