已知x/2=y/—3=z/4,求下列分式的值(1)(2x+3y+4z)/(4x+3y+2z)(2) (xy—yz+zx)/(x^2+y^2—z^2)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/14 17:58:01
已知x/2=y/—3=z/4,求下列分式的值(1)(2x+3y+4z)/(4x+3y+2z)(2) (xy—yz+zx)/(x^2+y^2—z^2)

已知x/2=y/—3=z/4,求下列分式的值(1)(2x+3y+4z)/(4x+3y+2z)(2) (xy—yz+zx)/(x^2+y^2—z^2)
已知x/2=y/—3=z/4,求下列分式的值
(1)(2x+3y+4z)/(4x+3y+2z)
(2) (xy—yz+zx)/(x^2+y^2—z^2)

已知x/2=y/—3=z/4,求下列分式的值(1)(2x+3y+4z)/(4x+3y+2z)(2) (xy—yz+zx)/(x^2+y^2—z^2)
设x/2=y/—3=z/4=k
x=2k
y=-3k
z=4k
(2x+3y+4z)/(4x+3y+2z)
=(2*2k-3*3k+4*4k)/(4*2k-3*3k+2*4k)
=11k/7k
=11/7
(xy—yz+zx)/(x^2+y^2—z^2)
=(-6k^2+12k^2+8k^2)/(4k^2+9k^2-16k^2)
=14k^2/(-3k^2)
=-14/3