tim xEz biet:

a)\(x^2+\left(y-\frac{1}{4}\right)^4=6\)

b)\(x+\left(\frac{-31}{12}\right)^2=\left(\frac{49}{12}\right)^2-x=y^2\)

c)\(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+11}=0\)

Tim x biet

a) \(\left(x+\frac{1}{4}-\frac{1}{3}\right):\) \(\left(2+\frac{1}{6}-\frac{1}{4}\right)=\frac{7}{46}\)

b) \(2\frac{1}{2}x+x=2\frac{2}{15}\)

Tim x biet

k) \(\left[\left(3,75:\frac{1}{4}+2\frac{2}{5}.125\%\right)-\left(\frac{7}{2}.0,8-1,2:\frac{3}{2}\right)\right]:\left(1\frac{1}{2}+0,75\right)x=64\)

tim x,y biet

a)\(\left(x-y-2\right)^2+7=\frac{14}{\left|y-1\right|+\left|y-3\right|}\)

Bai 1:a)Tim x biet\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\times\left(x+1\right)}=\frac{2009}{2011}\)    

b)\(\left(x-1\right)\times f\left(x\right)=\left(x+4\right)\times f\left(x\right)\)voi moi x

Bai 2;Tim x;y;z biet a)\(\frac{y+z+1}{x}=\frac{x+z+2}{y}=\frac{x+y-3}{z}\)     b)\(\frac{2x+1}{5}=\frac{3y-z}{7}=\frac{2x+3y-1}{6x}\)  

Tim x biet

\(\frac{3}{\left(x+2\right)\left(x+5\right)}+\frac{5}{\left(x+5\right)\left(\right)x+10}+\frac{7}{\left(x+10\right)\left(x+17\right)}=\frac{x}{\left(x+2\right)\left(x+17\right)}\)

Tim x biet

\(-5\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)

1) Tinh :a)  \(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}-\frac{50}{7}.\frac{\sqrt{0,49}}{25}\)

b) Tim x , biet: \(|2x-\frac{1}{5}|\left(-\frac{1}{5}\right)^5=\left(-\frac{1}{5}\right)^7\)

Tim x, biet:

a/ /x+\(\dfrac{1}{5}\)/-4=-2

b/ \(\dfrac{-15}{12}.x+\dfrac{3}{7}=\dfrac{6}{5}.x-\dfrac{1}{2}\)

c/ \(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+11}=0\)