\(0,81:\frac{x}{2}=\frac{16}{x^4}:0,9\)
\(\Rightarrow\frac{1,62}{x}=\frac{16}{x^4.0,9}\)
\(\Rightarrow1,62.0,9.x^4=16x\)
\(\Rightarrow1,458.x^4=16.x\)
\(\Rightarrow\frac{1,458}{16}=\frac{x}{x^4}\)
\(\Rightarrow0,091125=x^{-3}\)
1.Tìm x biết
a) \(\left(\frac{2}{5}-x\right)\):\(1\frac{1}{3}+\frac{1}{2}=-4\)
b) \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(1+\frac{2}{5}+\frac{2}{3}\right)=-\frac{5}{4}\)
c) \(\frac{-3x}{4}.\left(\frac{1}{x}+\frac{2}{7}\right)=0\)
d) 3-\(\frac{1-\frac{1}{2}}{1+\frac{1}{x}}=2\frac{2}{3}\)
e)\(\left(2x+\frac{1}{3}\right)^2=\frac{9}{16}\)
f) \(4^x+4^{x+3}=4160\)
g) \(\left(x-2,5\right):1\frac{1}{2}=x:2\)
h) \(\left(\frac{1}{3}+x\right):\left(x+\frac{3}{4}\right)=\frac{7}{9}\)
i) 0,81:\(\frac{x}{2}=\frac{16}{x^4}:\left(-0,9\right)\)
2. Tìm x, biết:
a)\(\left(152\frac{2}{4}-148\frac{3}{8}\right):0,2=x:0,3\)
b) \(\left[\left(6\frac{3}{5}-3\frac{3}{14}\right):2,5\right]:\left(21-1,25\right)=x:5\frac{5}{6}\)
Tìm x biết:
a) \(\frac{1}{4}+\frac{1}{3}:2x=-5\)
b) \(\left(3x-\frac{1}{4}\right).\left(x+\frac{1}{2}\right)=0\)
c) \(|x+\frac{1}{5}|-\frac{1}{2}=\frac{9}{10}\)
d) \(\sqrt{0,81}.\left(\sqrt{x}+\sqrt{\frac{16}{49}}\right)=\frac{9}{10}\)
f) \(|\frac{1}{3}.\sqrt{x+1}-\frac{2}{9}|-\frac{1}{6}=\frac{1}{9}\)
a) \(\frac{x+1}{2}\)+\(\frac{x+1}{3}\)+\(\frac{x+1}{4}\)=\(\frac{x+1}{5}\)+\(\frac{x+1}{6}\)
b) 0,81:\(\frac{x}{2}\)=\(\frac{16}{x^4}\): (-0,9)
Tìm số nguyên x biết \(\left(x^2-\frac{4}{25}\right)\left(x^2-4\right)\left(x^2-\frac{16}{9}\right)\left(x^2-10\right)< 10\)
Tìm x:
\(x:\left(-\frac{1}{3}\right)^3=-\frac{1}{3}\)
\(\left(\frac{4}{5}\right)^5.x=\left(\frac{4}{5}\right)^7\)
\(\left(x+\frac{1}{2}\right)^2=\frac{1}{16}\)
\(\left(3x+1\right)^3=-27\)
So sánh các số x và y, nếu
a)\(x=\sqrt{961}-\left(\frac{1}{\sqrt{6}}-1\right)\)và \(y=\sqrt{1089}-\left(\frac{1}{\sqrt{7}}+1\right)\)
b) \(\sqrt{0,01}+\sqrt{0,04}+\sqrt{0,09}+\sqrt{0,16}+...+\sqrt{0,81}\)và \(y=\sqrt{20+0,25}\)
c) \(x=\left(1-\frac{1}{\sqrt{4}}\right).\left(1-\frac{1}{\sqrt{16}}\right).\left(1-\frac{1}{\sqrt{36}}\right).\left(1-\frac{1}{\sqrt{64}}\right).\left(1-\frac{1}{\sqrt{100}}\right)\)và\(y=\sqrt{0,1}\)
Tìm x biết:
a, \(\left(x+\frac{2}{3}\right)^3-\frac{1}{8}=0\)
b, \(1-\left(2x+\frac{1}{2}\right)^2=\frac{3}{4}\)
c,\(\left(x-1\right)^4=16\)
tìm x biết:
\(\left(\frac{45\frac{10}{63}-44\frac{25}{84}}{\left(2\frac{1}{3}-1\frac{1}{9}\right):4-\frac{3}{4}}:31\right).x=\frac{-1}{16}\)
tìm x biết:
\(\left[\frac{45\frac{10}{63}-44\frac{25}{84}}{\left(2\frac{1}{3}-1\frac{1}{9}\right):4-\frac{3}{4}}:31\right].x=-\frac{1}{16}\)
