Tim x,y thuoc Z biet: \(2x+\frac{1}{7}=\frac{1}{y}\)
a, Tim x biet:/x-2/+/3-2x/=2x+1
b, Tim x,y thuoc Z biet:xy+2x-y=5
c, tim x,y,z, biet :2x=3y;4y=5zva 4x-3y+5z=7
Bai 1:a)Tim x biet\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\times\left(x+1\right)}=\frac{2009}{2011}\)
b)\(\left(x-1\right)\times f\left(x\right)=\left(x+4\right)\times f\left(x\right)\)voi moi x
Bai 2;Tim x;y;z biet a)\(\frac{y+z+1}{x}=\frac{x+z+2}{y}=\frac{x+y-3}{z}\) b)\(\frac{2x+1}{5}=\frac{3y-z}{7}=\frac{2x+3y-1}{6x}\)
tim x, y, z biet
1. \(\frac{x+y}{2015}=\frac{xy}{2016}=\frac{x-y}{2017}\)
2.\(\frac{2x+2}{3}=\frac{3y-1}{4}=\frac{4x+2}{5}\)va x+y+z=7
3.Tim x,y,z biet
a,\(\frac{x}{5}=\frac{y}{7};x.y=315\)
b,\(5x=9y;2x+3y=-33\)
c,\(\frac{x}{5}=\frac{y}{7}=\frac{z}{9};2x+y-3z=20\)
d,\(\frac{x}{4}=\frac{5}{y}=\frac{z}{6};2x^2-y^2+\frac{1}{2}z^2=100\)
e,\(\frac{x}{5}=\frac{y}{4}=\frac{7}{7};x+y-z=-10\)
g, 2x=5y=3z;x-y+z=38
a,tim x biet |x-2|+|3-2x|=2x+1
b,tim x,y thuoc Z biet xy+2x-y=5
c, tinh A=(1-1/15)(1-1/21)(1-1/28).....(1-1/210)
tim x thuoc Z de A thuoc Z va tim gia tri do A=\(\frac{1-2x}{x+3}\)
tim x y z biet
\(x:z=\frac{2}{3}:\frac{1}{2},z:y=1:\frac{4}{7}\&y+z=66\)
tim x,y,z biet
\(\frac{x}{y+z+1}=\frac{y}{z+x+1}=\frac{z}{x+y-2}=x+y+z\)
