a) ta có \(\frac{4-x}{6-x}=\frac{x-3}{x-8}\)=> \(\left(4-x\right).\left(x-8\right)=\left(x-3\right).\left(6-x\right)\)
=> \(\left(x-8\right).4-\left(x-8\right).x=\left(6-x\right).x-\left(6-x\right).3=4x-32-x^2-8x=6x-x^2-18-3x\)
=> \(4x+3x-x^2+x^2-8x-6x=32-18\)=> \(7x-\left(x^2-x^2\right)-8x-6x=14\)
=>\(7x-8x-6x=14\)=> \(-1x-6x=14\)=> -7x=14 => \(x=14:\left(-7\right)=-2\)
vậy x=-2
Tìm x biết
a) (8-5x).(x+2)+4.(x-2).(x+1)+2.(x-2).(x+2)=0
b)\(\left(-\frac{2}{5}+x\right):\frac{7}{9}+\left(-\frac{3}{5}+\frac{5}{6}\right):\frac{7}{9}=0\)
c)\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=1\frac{2003}{2004}\)
Tìm x biết:
a) \(\frac{1}{4}+\frac{1}{3}:2x=-5\)
b) \(\left(3x-\frac{1}{4}\right).\left(x+\frac{1}{2}\right)=0\)
c) \(|x+\frac{1}{5}|-\frac{1}{2}=\frac{9}{10}\)
d) \(\sqrt{0,81}.\left(\sqrt{x}+\sqrt{\frac{16}{49}}\right)=\frac{9}{10}\)
f) \(|\frac{1}{3}.\sqrt{x+1}-\frac{2}{9}|-\frac{1}{6}=\frac{1}{9}\)
B1.Tìm x
a) \(-x-\frac{3}{5}=\frac{7}{3}\)
b) \(\frac{4}{9}-x=\frac{-5}{3}\)
c) \(\frac{-9}{5}-\frac{6}{7}.x=\frac{2}{3}\)
d) \(\frac{3}{5}-\left(x-\frac{3}{5}\right)=\frac{4}{8}\)
e) \(\frac{-3}{8}-\left(\frac{4}{9}-x\right)=\frac{-2}{3}\)
1.Tìm x biết
a) \(\left(\frac{2}{5}-x\right)\):\(1\frac{1}{3}+\frac{1}{2}=-4\)
b) \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(1+\frac{2}{5}+\frac{2}{3}\right)=-\frac{5}{4}\)
c) \(\frac{-3x}{4}.\left(\frac{1}{x}+\frac{2}{7}\right)=0\)
d) 3-\(\frac{1-\frac{1}{2}}{1+\frac{1}{x}}=2\frac{2}{3}\)
e)\(\left(2x+\frac{1}{3}\right)^2=\frac{9}{16}\)
f) \(4^x+4^{x+3}=4160\)
g) \(\left(x-2,5\right):1\frac{1}{2}=x:2\)
h) \(\left(\frac{1}{3}+x\right):\left(x+\frac{3}{4}\right)=\frac{7}{9}\)
i) 0,81:\(\frac{x}{2}=\frac{16}{x^4}:\left(-0,9\right)\)
2. Tìm x, biết:
a)\(\left(152\frac{2}{4}-148\frac{3}{8}\right):0,2=x:0,3\)
b) \(\left[\left(6\frac{3}{5}-3\frac{3}{14}\right):2,5\right]:\left(21-1,25\right)=x:5\frac{5}{6}\)
Tìm x biết :
a)\(\frac{3}{2}x-\frac{1}{2}=\frac{2}{5}\) b)\(\frac{4}{5}-\left|x-\frac{2}{3}\right|=\frac{2}{3}\)
c)\(x=\left(2-\frac{15}{7}\right)^2+\left|\frac{-6}{7}\right|+\frac{\sqrt{36}}{49}\)
d)\(x=\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}\)
Các bn lm nhah giúp mik
thanks
tìm x
a) \(\frac{3}{4}+\frac{1}{4}.x=\frac{1}{2}+\frac{1}{2}.x\)
b) \(\frac{1}{3}.x-\frac{2}{5}.\left(x+1\right)=0\)
c)\(\left(\frac{1}{4}.x-1,5\right)+\left(\frac{5}{6}.x-3\right)-\left(\frac{5}{8}.x-0,5\right)=-4,5\)
\(3,2.\frac{15}{16}-\left(75\%+\frac{2}{7}\right):\left(-1\frac{1}{28}\right)\)
\(\left(0,25+12,5-\frac{5}{16}\right):\left[12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right]\)
\(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)
\(14,5-\frac{8}{9}:\left(35-34\frac{8}{9}\right).\frac{9}{8}\)
\(1\frac{1}{15}-\left(\frac{1}{15}+\frac{4}{9}:\frac{-2}{3}-\frac{28}{16}.\frac{6}{35}\right)-\frac{3}{10}\)
Tìm x
\(\left(4,5-2x\right)\left(-3\frac{2}{3}\right)=\frac{11}{15}\)
\(\backslash34-x\backslash=\left(-3\right)^4\)
\(\left(4x^2-1\right)\left(\text{\x}\backslash-\frac{2}{3}\right)=0\)
\(\frac{3}{5}x-\frac{1}{2}\)\(x=\frac{-7}{20}\)
1 Thực hiện phép tính :
a)\(2\frac{1}{5}.\frac{25}{4}-10\frac{1}{5}.\frac{24}{5}\)
b)\(5.(\frac{-2}{5})^2+2.\left(\frac{-2}{5}\right)+4.\left(\frac{-2}{5}\right)^0\)
c)\(\sqrt{\frac{16}{9}+}\left(\frac{2}{3}\right)^9:\left(\frac{-2}{3}\right)^8-/-2020/\)
2. tìm x,y,z biết :
a)\(\backslash-2x+\frac{1}{3}\backslash-\frac{1}{3}=2\frac{2}{3}\)
b) \(\frac{x-1}{x-5}=\frac{6}{7}\)
c) 2x=3y=5z và x+y-z=95
Tìm số nguyên x, nếu biết
\(\frac{^{2^{4-x}}}{16^5}=32^6\)
\(\frac{3^{2x+3}}{9^3}=9^{14}\)
\(\left(-2\right)^x=-\frac{\left(-8^4\right)}{\left(-32\right)^3}\)
\(\left(-5^x\right)=\frac{25^{10}}{\left(-5\right)^{17}}\)
