tim x,y,z biet y+z+1=x+z+2/y=x+y-3/2=1/x+y+z
tim x y biet X^2+y^2+1/y^2+1/x^2=4
tim hai so x va y biet x^2+y^2;x^2-y^2 va x^2.y^2 ti le nghich voi 1/25,1/7 va 1/576(x khac 0 va y khac 0)
Tim x,y,z biet:
1)|x|+|1-x|+|x+2|=5
2)|x-1/2|+|y+2\3|+|x^2+xz|=0
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 , y tu nhien biet (x^2+1)(2^x+2)(2^x+3)(2^x+4) +15^y=1679
tim x,y thuoc N* biet 1+x+x^2+x^3=2^y
tim x,y,z biet; x/z+y+1=y/x+z+1=x+y-2=x+y+z
Tim cap so x,y thoa man:
(x+y-2)^2 +7 = 14 / |y-1| + |y-3|
|x+y+2| + 5 = 30 / 3 |y+5| + 6
(2-x) (x+1) = |y+1|
(x+3) (1-x) = |y|
(x-2) (5-x) = |2y+1| + 2
Xac dinh a va b biet nghiem cua da thuc f(x) = (x-1) (x+2) cx la nghiem cua da thuc g(x) = x^3 + a x^2 + bx + 2
