Chứng minh rằng với mọi số tự nhiên n\(\ge\)1
A= (\(1+\frac{1}{1\cdot3}\))(\(1+\frac{1}{2\cdot4}\))(\(1+\frac{1}{3\cdot5}\))....\([1+\frac{1}{n\left(n+2\right)}]< 2\)
bài 2
a 0,75x (x +5 )= x+5 (3- 1,25x)
b\(\frac{4}{5}x-3=\frac{1}{5}x\left(4x-15\right)\)
c(x-3) -\(\frac{\left(x-3\right)\left(2x-5\right)}{6}=\frac{\left(x-3\right)\left(3-x\right)}{4}\)
d \(\frac{\left(3x+1\right)\left(3x-2\right)}{3}+5\left(3x+1\right)=\frac{2\left(2x+1\right)\left(3x+1\right)}{3}+2x\left(3x+1\right)\)
\(a.\frac{1}{9}\left(x-3\right)^2-\frac{1}{25}\left(x+5\right)^2=0\)
\(b.\left(\frac{3x}{5}-\frac{1}{3}\right)^2=\left(\frac{x}{5}+\frac{2}{3}\right)^2\)
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Giải các phương trình:
a) \(\frac{2x}{x-1}-\frac{x}{x-2}=\frac{x^2}{\left(x-1\right)\left(x-2\right)}\)
b) \(\frac{1}{x+2}-\frac{6}{x-1}+\frac{8}{\left(x+2\right)\left(x-1\right)}=0\)
c) \(\frac{x+2}{x+3}-\frac{x+1}{x-1}=\frac{4}{\left(x+3\right)\left(x-1\right)}\)
d) \(\frac{x-1}{x+2}-\frac{x+1}{x-2}=\frac{x-3}{4-x^2}\)
Bài 1:Giải phương trình
a)\(10x^2-5x\left(2x+3\right)=15\)
b)\(3x-7-\left(3-4x\right)\left(2x+1\right)=4x\left(2x-7\right)\)
c)\(\left(4x-5\right)^2-\left(7-2x\right)=4\left(2x-4\right)^2+6x\)
Bài 2:Giải phương trình
a)\(\frac{3\left(x-1\right)}{2}+4=\frac{2x}{3}+\frac{4-5x}{6}\)
b)\(\frac{4-x}{7}-\frac{1}{7}\left(\frac{7+3x}{9}+\frac{5-2x}{2}\right)=4-\frac{4x}{3}\)
c)\(\frac{2}{9}\left(2x-5\right)-\frac{5}{3}\left[\left(x-2\right)-\frac{7}{12}\right]=\frac{3}{4}\left(x-3\right)\)
Bài 3:Giải phương trình
a)\(\left(x-6\right)\left(2x-5\right)\left(3x+9\right)=0\)
b)\(2x\left(x-3\right)+5\left(x-3\right)=0\)
c)\(\left(x^2-4\right)-\left(x-2\right)\left(3-2x\right)=0\)
Bài 4:Tìm m để phương trình sau có nghiệm bằng 7:\(\left(2m-5\right)x-2m^2+8=43\)
Bài 5:Giải phương trình
a)\(\left(2x-1\right)^2-\left(2x+1\right)^2=0\)
b)\(\frac{1}{27}\left(x-3\right)^3-\frac{1}{125}\left(x-5\right)^3=0\)
giải phương trình sau :
a/ x + 1 = 3x - 1
b/x - 4 +2x = 4 - x
c/\(\frac{x+3}{4}+1=\frac{1-x}{6}\)
\(\frac{2x+3}{4}=1+\frac{x-7}{5}\)
\(^{\left(x+1\right)^2-\left(x-1\right)^2=2x\left(x+1\right)-6}\)
\(\left(1+x\right)^3-\left(x-2\right)^2=9\left(x-1\right)^2\)
Giải các phương trình sau:
a) \(\frac{12x+1}{6x-2}-\frac{9x-5}{3x+1}=\frac{108x-36x^2-9}{4\left(9x^2-1\right)}\)
b) \(x+\frac{1}{x}=x^2+\frac{1}{x^2}\)
c) \(\frac{1}{x}+2=\left(\frac{1}{x}+2\right)\left(x^2+2\right)\)
d) \(\left(x+1+\frac{1}{x}\right)^2=\left(x-1-\frac{1}{x}\right)^2\)
1) Giải các pt sau:
a) \(\frac{x-3}{5}=6-\frac{1-2x}{3}\)
b) \(\frac{3x-2}{6}-5=\frac{3-2\left(x+7\right)}{4}\)
c) \(\frac{x+8}{6}-\frac{2x-5}{5}=\frac{x-1}{3}-x+7\)
d) \(\frac{7x}{8}-5\left(x-9\right)=\frac{2x+1,5}{6}\)
e) \(\frac{5\left(x-1\right)+2}{6}-\frac{7x-1}{4}=\frac{2\left(2x+1\right)}{7}-5\)
f) \(\frac{x+1}{3}+\frac{3\left(2x+1\right)}{4}=\frac{2x+3\left(x+1\right)}{6}+\frac{7+12x}{12}\)
\(\frac{2}{x-1}\) + \(\frac{2x+3}{x^2+x+1}\) = \(\frac{\left[2x-1\right]\left[2x+1\right]}{x^{3^{ }}-1}\)
\(\frac{x^3-\left[x-1\right]^3}{\left[4x+3\right]\left[x-5\right]}\) = \(\frac{7x-1}{4x+3}\) - \(\frac{x}{x-5}\)
giả phương trình
