\(x^2-y^2=4z^2\\ \Leftrightarrow64z^2=16x^2-16y^2\)
\(\left(5x-3y+8z\right)\left(5x-3y-8z\right)\\ =\left(5x-3y\right)^2-64z^2\\ =25x^2-30xy+9y^2-64z^2\\ =25x^2-16x^2+9y^2+16y^2-30xy\\ =9x^2-30xy+25y^2=\left(3x-5y\right)^2\)
Cho x2=y2+4z2. Chứng minh: ( 5x-3y+8z)(5x-3y-8z)=(3x-5y)2
cho x^2 =y^2+4z^2 chứng minh (5x-3y+8z )(5x-3y-8z)+1 luôn Dương
CMR : Nếu x^2 - y^2 - z^2 = 0 thì ( 5x-3y+4z ) . ( 5x-3y - 4z ) = ( 3x - 5y )^2
cho x^2-y^2-z^2=0 chứng minh rằng: (5x-3y+4z)*(5x-3y-4z)=(3x-5y)^2
Cho \(^{x^2-y^2-z^2=0.CMR:\left(5X-3Y+4Z\right)\left(5Z-3Y-4Z\right)=\left(3X-5Y\right)^2}\)
a) cho x^2 = y^2+z^2. chứng minh: (5x-3y+4z)(5x-3y-4z)=(3x-5y)^2
b) cho 10x^2=10y^2+z^2. chứng minh: (7x-3y+2z)(7x-3y-2z)=(3x-7y)^2
Cho x2-y2-z2=0
C/m (5x-3y+4z).(5x-3y-4z)=(3x-5y)2
cho x2-y2-z2=0
chúng minh : (5x-3y+4z)(5x-3y-4z)=(3x-5y)2
Nếu x2=y2+z2. chứng minh rằng (5x-3y+4z)(5x-3y-4z)=(3x-5y)2
