\(\frac{12-3x}{32}=\frac{6}{4-x}\)
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vì ta có 12-3x/32 =12-3 nhân x
mà rút gon lại bằng 6 ,còn 32 rút gọn lại bằng 4 nên x=0
VD: 12-3 nhân 0 /32
=12-0 / 32
=12 / 32 và rút gọn bằng 6/4
nên x=0
hok tốt
\(\frac{12-3x}{32}=\frac{6}{4-x}ĐK:x\ne4\)
\(\Leftrightarrow\frac{\left(12-3x\right)\left(4-x\right)}{32\left(4-x\right)}=\frac{192}{32\left(4-x\right)}\)
\(\Leftrightarrow48-12x-12x+3x^2=192\)
\(\Leftrightarrow48-24x+3x^2=192\)Xử nốt nhé, dễ rồi!!!
#)Giải :
a) x + 2x + 3x + ... + 100x = - 213
=> 100x + ( 2 + 3 + 4 + ... + 100 ) = - 213
=> 100x + 5049 = - 213
<=> 100x = - 5262
<=> x = - 52,62
#)Giải :
b) \(\frac{1}{2}x-\frac{1}{3}=\frac{1}{4}x-\frac{1}{6}\)
\(\Rightarrow\frac{1}{2}x+\frac{1}{4}x=\frac{1}{3}+\frac{1}{6}\)
\(\Rightarrow\frac{1}{2}x+\frac{1}{4}x=\frac{1}{2}\)
\(\Rightarrow\left(\frac{1}{2}+\frac{1}{4}\right)x=\frac{1}{2}\)
\(\Rightarrow\frac{3}{4}x=\frac{1}{2}\)
\(\Leftrightarrow x=\frac{2}{3}\)
a) \(\frac{36\left(x-2\right)}{32-16x}=\frac{36\left(x-2\right)}{16\left(2-x\right)}=-\frac{36\left(2-x\right)}{16\left(2-x\right)}=-\frac{36}{16}=-\frac{9}{4}\)
b) \(\frac{3x^2-12x+12}{x^4-8x}=\frac{3\left(x^2-4x+4\right)}{x\left(x^3-8\right)}=\frac{3\left(x-2\right)^2}{x\left(x-2\right)\left(x^2+2x+4\right)}=\frac{3\left(x-2\right)}{x\left(x^2+2x+4\right)}=\frac{3x-6}{x^3+2x^2+4x}\)
c) \(\frac{7x^2+14x+7}{3x^2+3x}=\frac{7\left(x^2+2x+1\right)}{3x\left(x+1\right)}=\frac{7\left(x+1\right)^2}{3x\left(x+1\right)}=\frac{7\left(x+1\right)}{3x}=\frac{7x+7}{3x}\)
d) \(\frac{x^4-5x^2+4}{x^4-10x^2+9}=\frac{x^4-x^2-4x^2+4}{x^4-x^2-9x^2+9}=\frac{x^2\left(x^2-1\right)-4\left(x^2-1\right)}{x^2\left(x^2-1\right)-9\left(x^2-1\right)}=\frac{\left(x^2-4\right)\left(x^2-1\right)}{\left(x^2-9\right)\left(x^2-1\right)}=\frac{\left(x-2\right)\left(x+2\right)}{\left(x-3\right)\left(x+3\right)}\)
e) \(\cdot\frac{x^4+x^3+x+1}{x^4-x^3+2x^2-x+1}=\frac{x^3\left(x+1\right)+\left(x+1\right)}{x^4-x^3+x^2+x^2-x+1}=\frac{\left(x^3+1\right)\left(x+1\right)}{x^2\left(x^2-x+1\right)+\left(x^2-x+1\right)}=\frac{\left(x+1\right)^2\left(x^2-x+1\right)}{\left(x^2+1\right)\left(x^2-x+1\right)}=\frac{\left(x+1\right)^2}{x^2+1}=\frac{x^2+2x+1}{x^2+1}\)
\(ĐKXĐ:x\ne\pm2\)
\(\frac{x}{x+2}+\frac{6}{2-x}=\frac{3x-12}{x^2-4}\)
\(\Leftrightarrow\frac{x}{x+2}-\frac{6}{x-2}-\frac{3x-12}{\left(x-2\right)\left(x+2\right)}=0\)
\(\Leftrightarrow\frac{x\left(x-2\right)-6\left(x+2\right)-\left(3x-12\right)}{\left(x-2\right)\left(x+2\right)}=0\)
\(\Leftrightarrow x^2-2x-6x-12-3x+12=0\)
\(\Leftrightarrow x^2-11x=0\)
\(\Leftrightarrow x\left(x-11\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-11=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=11\end{cases}}\)(tm)
Vậy tập nghiệm của phương trình là \(S=\left\{0;11\right\}\)
\(ĐKXĐ:x\ne\pm2\)
\(\frac{x}{x+2}+\frac{6}{2-x}=\frac{3x-12}{x^2-4}\)
\(\Leftrightarrow\frac{x}{x+2}+\frac{-6}{x-2}-\frac{3x-12}{\left(x-2\right)\left(x+2\right)}=0\)
\(\Leftrightarrow\frac{x\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}+\frac{-6\left(x+2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{3x-12}{\left(x-2\right)\left(x+2\right)}=0\)
\(\Leftrightarrow\frac{x\left(x-2\right)-6\left(x+2\right)-\left(3x-12\right)}{\left(x-2\right)\left(x+2\right)}=0\)
\(\Leftrightarrow x\left(x-2\right)-6\left(x+2\right)-\left(3x-12\right)=0\)
\(\Leftrightarrow x^2-2x-6x-12-3x+12=0\)
\(\Leftrightarrow x^2-11x=0\)\(\Leftrightarrow x\left(x-11\right)=0\)\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-11=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=11\end{cases}}\)( thoả mãn \(ĐKXĐ\))
Vậy tập nghiệm của phương trình là \(S=\left\{0;11\right\}\)
\(\frac{12-3x}{32}=\frac{6}{4-x}\)
\(\Rightarrow\left(12-3x\right)\left(4-x\right)=6\times32\)
\(\Rightarrow3\left(4-x\right)\left(4-x\right)=192\)
\(\Rightarrow3\left(4-x\right)^2=192\)
\(\Rightarrow\left(4-x\right)^2=192\div3\)
\(\Rightarrow\left(4-x\right)^2=64\)
\(\Rightarrow\left(4-x\right)^2=8^2\)
\(\Rightarrow\orbr{\begin{cases}4-x=-8\\4-x=8\end{cases}\Rightarrow\orbr{\begin{cases}x=4+8\\x=4-8\end{cases}\Rightarrow}\orbr{\begin{cases}x=12\\x=-4\end{cases}}}\)
Vậy \(x=12;x=-4\)