(x - 1)2 = (x - 1)4 => (x - 1)4 - (x - 1)2 = 0
Ta có 2 trường hợp:
TH1: (x - 1)4 = (x - 1)2 = 0 => x - 1 = 0 => x = 1
TH2: (x - 1)4 = (x - 1)2 > 0.
x - 1 chỉ có thể là 1 hoặc -1 . Vì (-1)n đều = 1, nhưng các số khác thì lại khác nhau.
*) x - 1 = 1 => x = 2
*) x - 1 = -1 => x = 0
Vậy x thuộc {2; 0; 1}
Tim x,y nguyen biet \(\left(x+1\right)\left(x-1\right)=2y^2\)
tim x biet
\(\left(x-\frac{1}{3}\right).\left(y-\frac{1}{2}\right).\left(z-5\right)=0\)
và x+2=y+1=z+3
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:
\(x+1=y+2=z+3và\left(x-\frac{1}{5}\right)\left(y+\frac{1}{3}\right)\left(z-6\right)=0\)
tim x biet :
x-128 = \(\left(4\frac{20}{21}-5\right):\left(\frac{4141}{4242}-1\right):\left(\frac{636363}{646464}-1\right)\)
Tim x biet : \(\left(x-3\right)^2=\left(2x-1\right)^2\)
Tim x biet neu \(\frac{x-2}{\left(a+3\right)\left(a-5\right)}=\frac{1}{2\left(a+3\right)}+\frac{1}{2\left(a+5\right)}\)
va x khac -3;5
bai 1: Tim x biet
\(\hept{\begin{cases}x-y=\frac{3}{10}\\y\left(x-y\right)=-\frac{3}{50}\end{cases}}\)
bai 2: Tim x, y biet:
x+\(\left(-\frac{31}{12}\right)^2\)=\(\left(\frac{49}{12}\right)^2\)-x=y2
Bai 9: Tim x,y,z biet:
(x-1)2+(x+y)2+(xy-z)2=0
tim x biet
\(\left(1^2+2^2+3^2+...+49^2\right)\left(2-x\right)\)=6/5
