tim x biết \(\frac{x-1}{x+2}=\frac{x-2}{x+3}\)
Những câu hỏi liên quan
Tim x
\(\frac{x+2015}{5}+\frac{x+2016}{4}=\frac{x+2017}{3}+\frac{x+2018}{2}\)
2/ tim x
\(\frac{x+2015}{5}+\frac{x+2016}{6}=\frac{x+2017}{7} +\frac{x+2018}{8}\)
3/ tim x
\(\frac{1}{3}+\frac{1}{6}+\frac{99}{101}+\frac{1}{15}+... +\frac{1}{x\left(2x+1\right)}=\frac{1}{10}\)
\(\frac{x+2015}{5}+\frac{x+2016}{4}=\frac{x+2017}{3}+\frac{x+2018}{2}\)
\(\Leftrightarrow\left(\frac{x+2015}{5}+1\right)+\left(\frac{x+2016}{4}+1\right)=\left(\frac{x+2017}{3}+1\right)+\left(\frac{x+2018}{2}+1\right)\)
\(\Leftrightarrow\frac{x+2020}{5}+\frac{x+2020}{4}-\frac{x+2020}{3}-\frac{x+2020}{2}=0\)
\(\Leftrightarrow\left(x+2020\right)\left(\frac{1}{5}+\frac{1}{4}-\frac{1}{3}-\frac{1}{2}\right)=0\)
\(\Leftrightarrow x+2020=0\)vì \(\frac{1}{5}+\frac{1}{4}+\frac{1}{3}+\frac{1}{2}\ne0\)
\(\Leftrightarrow x=-2020\)
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Cảm ơn bạn rất nhiều mình đã hiểu rồi
Chúc bạn học tốt nhé
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Xem thêm câu trả lời
Tim x:
\(x-\frac{\frac{x}{2}-\frac{x}{3}}{4}-\frac{x}{6}=\frac{2\left(1+x\right)}{3}-\frac{\frac{x}{3}+\frac{1-x^7}{4}}{2}\)
Tim x,y,z biết:
\(\frac{x+z+2}{x}=\frac{x+z+3}{y}=\frac{x+z+5}{z}=\frac{2}{x+y+z}\)
Tim x biết
\(\frac{3}{x-2}\)=\(\frac{-2}{\frac{1}{8}}\)
\(\frac{3}{x-2}=\frac{-2}{\frac{1}{8}}\)
\(\Rightarrow\frac{3}{8}=-2\left(x-2\right)\)
\(\frac{3}{8}=-2x-\left(-4\right)\)
\(\frac{3}{8}=-2x+4\)
\(-2x=\frac{3}{8}-4=\frac{-29}{8}\)
\(x=\frac{-29}{8}.\frac{1}{-2}=\frac{29}{16}\)
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\(\frac{3}{x-2}=-\frac{2}{\frac{1}{8}}\)
\(\Rightarrow\frac{3}{x-2}=\frac{\left(-2\right).8}{1}\)
\(\Rightarrow\frac{3}{x-2}=-16\)
\(\Rightarrow x-2=3:\left(-16\right)\)
\(\Rightarrow x-2=-\frac{3}{16}\)
\(\Rightarrow x=-\frac{3}{16}+2\)
\(\Rightarrow x=\frac{29}{16}\)
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=> 3 x 1/8 = -2(x - 2)
=> -2(x - 2) = 3/8
=>x -2 = -3/16
=> x= 29/16
k nhé!
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tim x
\(\frac{2^x+2^{x+1}+2^{x+2}}{7}=\frac{3^x+3^{x+1}+3^{x+2}}{13}\)
Ta có\(\frac{2^x+2^{x+1}+2^{x+2}}{7}=\frac{3^x+3^{x+1}+3^{x+2}}{13}\)
\(\Rightarrow\frac{2^x\left(1+2+2^2\right)}{7}=\frac{3^x\left(1+3+3^2\right)}{13}\)
\(\Rightarrow\frac{2^x\left(1+2+4\right)}{7}=\frac{3^x\left(1+3+9\right)}{13}\)
\(\Rightarrow\frac{2^x.7}{7}=\frac{3^x.13}{13}\)
\(\Rightarrow2^x=3^x\)
\(\Rightarrow x=0\)
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Tim x biet
c) \(x-3\frac{1}{2}x=-2\frac{6}{7}\)
d) \(-2\frac{1}{3}x-1\frac{3}{4}x+3\frac{2}{3}=3\frac{3}{5}\)
Tim x biet
\(-5\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)
-5.(x+1/5) -1/2.(x-2/3)=3/2x-5/6
-5x + (-1) -1/2x -1/3=3/2x-5/6
-5x-1/2x-3/2x=1+1/3-5/6
x.(-5-1/2-3/2)= 6/6+2/6+(-5/6)
x.(-10/2+(-1/2)+(-3/2))=3/6
x.6/2=1/2
x=1/2:6/2
x=1/6
Vậy x = 1/6
cho biểu thức A left(frac{3}{4}+frac{3}{x^2+3x}right)chialeft(frac{x^2}{27-3x}+frac{1}{x+3}right)a, rut gon A b, tim x de a-1c, tim cac gia tri nguyen cua x de A co gia tri nguyencho bthuc B left(frac{x^2}{x^3-4x}+frac{6}{6-3x}+frac{1}{x-2}right)chialeft(x-2+frac{16-x^2}{x+2}right)rut gon B tính b khi /x/ 1/2tim x de b2tim x in z de b in z
Đọc tiếp
cho biểu thức A= \(\left(\frac{3}{4}+\frac{3}{x^2+3x}\right)chia\left(\frac{x^2}{27-3x}+\frac{1}{x+3}\right)\)
a, rut gon A
b, tim x de a<-1
c, tim cac gia tri nguyen cua x de A co gia tri nguyen
cho bthuc B = \(\left(\frac{x^2}{x^3-4x}+\frac{6}{6-3x}+\frac{1}{x-2}\right)chia\left(x-2+\frac{16-x^2}{x+2}\right)\)rut gon B tính b khi /x/ = 1/2tim x de b=2tim x \(\in\) z de b \(\in\) z
Bài 2:
a: \(B=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{6}{3\left(x-2\right)}+\dfrac{1}{x-2}\right):\left(\dfrac{x^2-4+16-x^2}{x+2}\right)\)
\(=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{2}{x-2}+\dfrac{1}{x-2}\right):\dfrac{12}{x+2}\)
\(=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{1}{x-2}\right):\dfrac{12}{x+2}\)
\(=\dfrac{x-x-2}{\left(x-2\right)\left(x+2\right)}\cdot\dfrac{x+2}{12}=\dfrac{-1}{6\left(x-2\right)}\)
b: Thay x=1/2 vào B, ta được:
\(B=\dfrac{-1}{6\cdot\left(\dfrac{1}{2}-2\right)}=\dfrac{-1}{6\cdot\dfrac{-3}{2}}=\dfrac{1}{9}\)
Thay x=-1/2 vào B, ta được:
\(B=\dfrac{-1}{6\cdot\left(-\dfrac{1}{2}-2\right)}=-\dfrac{1}{15}\)
c: Để B=2 thì \(\dfrac{-1}{6\left(x-2\right)}=2\)
=>6(x-2)=-1/2
=>x-2=-1/12
hay x=23/12
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Tim x
\(-2\frac{1}{3}x-1\frac{3}{4}x+3\frac{2}{3}=3\frac{3}{5}\)