(2x - 1)3 + 6(3x - 1)2 = 2(x + 1)3 + 6(x + 2)3
<=> 8x3 - 12x2 + 6x - 1 + 6(9x2 - 6x + 1) = 2(x3 + 3x2 + 3x + 1) + 6(x3 + 6x2 + 12x + 8)
<=> 8x3 -12x2 + 6x - 1 + 54x2 - 36x + 6 = 2x3 + 6x2 + 6x + 2 + 6x3 + 36x2 + 72x + 48
<=> 8x3 -12x2 + 6x - 1 + 54x2 - 36x + 6 - 2x3 - 6x2 - 6x - 2 - 6x3 - 36x2 - 72x - 48 = 0
<=> -108x - 45 = 0
<=> -108x = 45
<=> x = \(\frac{45}{-108}\)
<=> x = \(\frac{-45}{108}\)
<=> x = \(\frac{-5}{12}\)
Vậy nghiệm của phương trình là x = \(\frac{-5}{12}\)
Giải các phương trình sau:
1. \(a,\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{8}{2x-6}\)
\(b,\dfrac{1}{x-2}+\dfrac{5}{x+1}=\dfrac{3}{2-x}\)
\(c,\dfrac{3x}{x-2}-\dfrac{x}{x-5}=\dfrac{3x}{\left(x-2\right)\left(5-x\right)}\)
2. \(a,\left(x+2\right)\left(3-4x\right)=x^2+4x+4\)
\(b,2x^2-6x+1\)
Giải phương trình:
\(a,\left|-5x\right|=3x-16\)
\(b,\left|2x+1\right|=\left|x-1\right|\)
\(c,\left|2x+1\right|-\left|5x-2\right|=3\)
Giải bất phương trình :
a) \(\frac{x}{3}\left(\frac{16x}{3}-4\right)-\left(\frac{5x}{3}-1\right)^2\ge0\)
b) \(\left(3x^2-2\right)+6\left(2x+1\right)>3x\left(x+4\right)\)
Chứng minh biểu thức sau không phụ thuộc vào giá trị của biến :
\(A=x.\left(5x-3\right)-x^2.\left(x-1\right)+x.\left(x^2-6x\right)-10+3x+x.\left(x^2+x+1\right)-x^2.\left(x+1\right)-x+5\)
\(B=3.\left(2x-1\right)-5.\left(x-3\right)+6.\left(3x-4\right)-19x+x.\left(3x+12\right)-\left(7x-20\right)+x^2.\left(2x-3\right)-x.\left(2x^2+5\right)\)
Bài 1: Giải phương trình
\(a,\dfrac{x+1}{2009}+\dfrac{x+3}{2007}=\dfrac{x+5}{2005}+\dfrac{x+7}{1993}\)
\(b,\left(x+2\right)^4+\left(x+4\right)^4=14\)
\(c,\left(x-3\right)\left(x-2\right)x+1=60\)
d, \(2x^4+3x^3-x^2+3x+2=0\)
Giải các phương trình sau
a) \(\frac{1}{x+1}-\frac{5}{x-2}=\frac{15}{\left(x+1\right)\left(2-x\right)}\)
b) \(\frac{1}{2x-3}-\frac{3}{x\left(2x-3\right)}=\frac{5}{x}\)
c) \(\frac{6}{x-1}-\frac{4}{x-3}=\frac{8}{2x-6}\)
d) \(\frac{3}{\left(x-1\right)\left(x-2\right)}+\frac{2}{\left(x-3\right)\left(x-1\right)}=\frac{1}{\left(x-2\right)\left(x-3\right)}\)
e) \(\frac{1}{x-2}+\frac{5}{x+1}=\frac{3}{2-x}\)
f) \(\frac{5x}{2x+2}+1=-\frac{6}{x+1}\)
g) \(\frac{x+1}{x-1}-\frac{x-1}{x+1}=\frac{4}{x^2-1}\)
h) \(\frac{3x}{x-2}-\frac{x}{x-5}=\frac{3x}{\left(x-2\right)\left(5-x\right)}\)
Giải các bất phương trình sau :
a) \(15-2x\left(1-x\right)< 2x^2-4x+5\)
b) \(x^2-\frac{x\left(3x+2\right)}{3}< \frac{x-6}{3}\)
c) \(1+\frac{x+4}{3}< x-\frac{x-3}{2}\)
d) \(\left(\frac{2x+1}{2}\right)^2+\frac{3x\left(1-x\right)}{3}-\frac{5x}{4}\le1\)
giải pt sau
a)\(\left(x-2\right)\left(x-3\right)+2x=\left(x-2\right)^2-2\)
b) \(\left(x-1\right)^2+3x\left(x-1\right)+7=\left(2x-1\right)^2+5\left(x-3\right)\)
c)\(5\left(x^1-2x-1\right)+2\left(3x-2\right)=5\left(x+1\right)^2\)
d)\(\left(x-1\right)\left(x^2+x+1\right)-2x=x\left(x-1\right)\left(x+1\right)\)
Giải phương trình sau:
\(^{\left(x^2+1\right)^2}\)+3x\(^{\left(x^2+1\right)^2}\)+\(^{2x^2}\)=0