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\(1a,\frac{\left(2x+1\right)^2}{5}-\frac{\left(x-1\right)^2}{3}=\frac{7x^2-14x-5}{15}\)
\(\Leftrightarrow\frac{3\left(2x+1\right)^2}{15}-\frac{5\left(x-1\right)^2}{15}=\frac{7x^2-14x-5}{15}\)
\(\Leftrightarrow\frac{12x^2+12x+3}{15}-\frac{5x^2-10x+5}{15}=\frac{7x^2-14x-5}{15}\)
\(\Leftrightarrow12x^2+12x+3-5x^2+10x-5=7x^2-14x-5\)
\(\Leftrightarrow36x=-3\)
\(x=-\frac{1}{12}\)
Vậy ................
\(b,\frac{7x-1}{6}+2x=\frac{16-x}{5}\)
\(\Leftrightarrow\frac{5\left(7x-1\right)}{30}+\frac{30.2x}{30}=\frac{6\left(16-x\right)}{30}\)
\(\Leftrightarrow35x-5+60x=96-6x\)
\(\Leftrightarrow101x=101\)
\(\Leftrightarrow x=1\)
Vậy ....................
a:=>x^2-1-x=2x-1
=>x^2-x-1=2x-1
=>x^2-3x=0
=>x=0(loại) hoặc x=3(nhận)
b:=>x+2=0 hoặc 5-3x=0
=>x=-2 hoặc x=5/3
c:=>20(1-2x)+6x=9(x-5)-24
=>20-40x+6x=9x-45-24
=>-34x+20=9x-69
=>-43x=-89
=>x=89/43
d: =>x^2+4x+4-x^2-2x+3=2x^2+8x-4x-16-3
=>2x^2+4x-19=-2x+7
=>2x^2+6x-26=0
=>x^2+3x-13=0
=>\(x=\dfrac{-3\pm\sqrt{61}}{2}\)
e: =>(2x-3)(2x-3-x-1)=0
=>(2x-3)(x-4)=0
=>x=4 hoặc x=3/2
Bạn đưa quá nhiều bài 1 lúc nên người ta giải được cũng chẳng ai muốn giải đâu, vì nhìn vào đã thấy ngộp rồi. Kinh nghiệm là muốn được giải quyết nhanh thì chỉ đăng 2-3 bài 1 lúc thôi
Bài 1:
a/ \(11-\left(2x+3\right)=3\left(x-4\right)\)
\(\Leftrightarrow11-2x-3=3x-12\)
\(\Leftrightarrow5x=20\)
\(\Rightarrow x=4\)
b/ \(5\left(2x-3\right)-4\left(5x-7\right)=19-2x\)
\(\Leftrightarrow10x-15-20x+28=19-2x\)
\(\Leftrightarrow8x=-6\)
\(\Rightarrow x=-\frac{3}{4}\)
c/
\(\frac{x}{3}-\frac{2x+1}{2}=\frac{x}{6}-x\)
\(\Leftrightarrow2x-3\left(2x+1\right)=x-6x\)
\(\Leftrightarrow x=3\)
d/
\(\frac{5x+2}{6}-\frac{8x-1}{3}=\frac{4x+2}{5}-5\)
\(\Leftrightarrow5\left(5x+2\right)-10\left(8x-1\right)=6\left(4x+2\right)-150\)
\(\Leftrightarrow79x=158\)
\(\Rightarrow x=2\)
e/
\(\frac{2-6x}{5}-\frac{2+3x}{10}=7-\frac{6x+3}{4}\)
\(\Leftrightarrow4\left(2-6x\right)-2\left(2+3x\right)=140-5\left(6x+3\right)\)
\(\Leftrightarrow0=-121\) (vô lý)
Vậy pt vô nghiệm
f/
\(\frac{3x+2}{2}-\frac{3x+1}{6}=2x+\frac{5}{3}\)
\(\Leftrightarrow3\left(3x+2\right)-\left(3x+1\right)=12x+10\)
\(\Leftrightarrow6x=-5\)
\(\Rightarrow x=-\frac{5}{6}\)
e)
=> (x-2) . (x+7) = ( x-1 ) . ( x +4)
=> x2 +7x - 2x -14 = x2 - x + 4x - 4
x2 + 5x - 14 = x2 + 3x - 4
=> 5x - 14 = 3x - 4
=> 5x - 3x = 14-4
=> 2x = 10 => x = 10 : 2 => x = 5
c)
=>( x-1) . 7 = ( x + 5 ) . 6
=> 7x - 7 = 6x + 30
=> 7x - 6x= 30 + 7
=> x = 37
a,x=\(\frac{5}{2}\)
b,x=\(\frac{13}{176}\)
c,x=37
d, x=\(\frac{12}{5}\)
e, x=5
Bài 1:
a/ \(x\ne1;2\)
\(\frac{x-2}{\left(x-1\right)\left(x-2\right)}-\frac{7\left(x-1\right)}{\left(x-1\right)\left(x-2\right)}+\frac{1}{\left(x-1\right)\left(x-2\right)}=0\)
\(\Leftrightarrow x-2-7x+7+1=0\)
\(\Leftrightarrow-6x+6=0\)
\(\Rightarrow x=1\) (loại)
Vậy pt vô nghiệm
b/ \(x\ne\frac{3}{2}\)
\(\frac{2x+3}{2x-3}-\frac{3}{2\left(2x-3\right)}-\frac{2}{5}=0\)
\(\Leftrightarrow\frac{10\left(2x+3\right)}{10\left(2x-3\right)}-\frac{15}{10\left(2x-3\right)}-\frac{4\left(2x-3\right)}{10\left(2x-3\right)}=0\)
\(\Leftrightarrow20x+30-15-8x+12=0\)
\(\Leftrightarrow12x+27=0\)
\(\Rightarrow x=-\frac{9}{4}\)
c/ \(x\ne\pm1\)
\(\frac{x+1}{x-1}-\frac{4}{x+1}+\frac{3-x^2}{x^2-1}=0\)
\(\Leftrightarrow\frac{\left(x+1\right)^2}{x^2-1}-\frac{4\left(x-1\right)}{x^2-1}+\frac{3-x^2}{x^2-1}=0\)
\(\Leftrightarrow x^2+2x+1-4x+4+3-x^2=0\)
\(\Leftrightarrow-2x+8=0\)
\(\Rightarrow x=4\)
Bài 1:
d/\(x\ne\pm3\)
\(\frac{x-1}{x+3}-\frac{x}{x-3}+\frac{7x-3}{x^2-9}=0\)
\(\Leftrightarrow\frac{\left(x-1\right)\left(x-3\right)}{x^2-9}-\frac{x\left(x+3\right)}{x^2-9}+\frac{7x-3}{x^2-9}=0\)
\(\Leftrightarrow x^2-4x+3-x^2-3x+7x-3=0\)
\(\Rightarrow0=0\)
Vậy pt có vô số nghiệm \(x\ne\pm3\)
e/ \(x\ne\pm1\)
\(\frac{1}{x+1}+\frac{2}{x^2\left(x-1\right)-\left(x-1\right)}+\frac{3}{x^2-1}=0\)
\(\Leftrightarrow\frac{1}{x+1}+\frac{2}{\left(x^2-1\right)\left(x-1\right)}+\frac{3}{x^2-1}=0\)
\(\Leftrightarrow\frac{1}{x+1}+\frac{2}{\left(x+1\right)\left(x-1\right)^2}+\frac{3}{\left(x-1\right)\left(x+1\right)}=0\)
\(\Leftrightarrow\frac{\left(x-1\right)^2}{\left(x+1\right)\left(x-1\right)^2}+\frac{2}{\left(x+1\right)\left(x-1\right)^2}+\frac{3\left(x-1\right)}{\left(x+1\right)\left(x-1\right)^2}=0\)
\(\Leftrightarrow x^2-2x+1+2+3x-3=0\)
\(\Leftrightarrow x^2+x=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=-1\left(l\right)\end{matrix}\right.\)
\(a\text{) }7-\left(2x+4\right)=-\left(x+4\right)\)
\(\Leftrightarrow7-2x-4=-x-4\)
\(\Leftrightarrow x=7\)
\(b\text{) }\frac{3x-1}{3}=\frac{2-x}{2}\)
\(\Leftrightarrow2\left(3x-1\right)=3\left(2-x\right)\)
\(\Leftrightarrow6x-2=6-3x\)
\(\Leftrightarrow9x=8\Leftrightarrow x=\frac{8}{9}\)
\(c\text{) }\frac{2\left(3x+5\right)}{3}-\frac{x}{2}=5-\frac{3\left(x+1\right)}{4}\)
\(\Leftrightarrow8\left(3x+5\right)-6x=60-9\left(x+1\right)\)
\(\Leftrightarrow24x+40-6x=60-9x-9\)
\(\Leftrightarrow27x=11\Leftrightarrow x=\frac{11}{27}\)
\(d\text{) }x^2-4x+4=9\)
\(\Leftrightarrow\left(x-2\right)^2=3^2\)
\(\Leftrightarrow x-2=3\Leftrightarrow x=5\)
\(e\text{) }\frac{x-1}{x+2}-\frac{x}{x-2}=\frac{5x-8}{x^2-4}\)
\(\Leftrightarrow\left(x-2\right)\left(x-1\right)-x\left(x+2\right)=5x-8\)
\(\Leftrightarrow x^2-x-2x+3-x^2-2x=5x-8\)
\(\Leftrightarrow11-10x=0\Leftrightarrow x=\frac{11}{10}\)
a, \(\frac{1}{2}-\frac{3}{5}x=4-\frac{1}{3}x\)
<=> \(\frac{1}{2}-\frac{3}{5}x+\frac{1}{3}x=4\)
<=>\(\frac{1}{2}-x.\left(\frac{3}{5}-\frac{1}{3}\right)=4\)
<=>\(\frac{1}{2}-\frac{4}{15}x=4\)
<=>\(\frac{4}{15}x=\frac{1}{2}-4\)
<=>\(\frac{4}{15}x=\frac{-7}{2}\)
<=> x = \(\frac{-7}{2}:\frac{4}{15}\)
<=> x = \(\frac{-7}{2}.\frac{15}{4}\)
<=> x = \(\frac{-105}{8}\)
b,\(\left(x^2-5\right).x^2=0\)
<=> \(x^2-5=0:x^2\)
<=>\(x^2-5=0\)
<=> \(x^2=5\)
<=> x = 5:x
c, 2 . I x - \(\frac{1}{2}\)I = \(\frac{-1}{3}+5\frac{1}{3}\)
<=>2 . I x - \(\frac{1}{2}\)I = \(\frac{-1}{3}+\frac{5}{3}\)
<=>2 . I x - \(\frac{1}{2}\)I = \(\frac{4}{3}\)
<=> I x - \(\frac{1}{2}\)I = \(\frac{4}{3}:2\)
<=> I x - \(\frac{1}{2}\)I = \(\frac{4}{3}.\frac{1}{2}\)
<=> I x - \(\frac{1}{2}\)I = \(\frac{2}{3}\)
=> x - \(\frac{1}{2}\)= \(\frac{2}{3}\)hoặc x - \(\frac{1}{2}\)= \(\frac{-2}{3}\)
TH1: x -\(\frac{1}{2}\) = \(\frac{2}{3}\)
<=> x = \(\frac{2}{3}\)+ \(\frac{1}{2}\)
<=> x = \(\frac{7}{6}\)
TH2: x - \(\frac{1}{2}\)= \(\frac{-2}{3}\)
<=> x = \(\frac{-2}{3}\)+ \(\frac{1}{2}\)
<=> x = \(\frac{-1}{6}\)
d) I 2x - 3 I - x = 6
=> 2x - 3 - x = 6 hoặc 2x - 3 - x = - 6
TH1:2x - 3 - x = 6
<=> x - 3 = 6
<=> x = 6 + 3
<=> x = 9
TH2: 2x - 3 - x = - 6
<=> x - 3 = -6
<=> x = - 6 + 3
<=> x = - 3
+ I 2x - 3 I