x:y=5:3 x:z=7:3 2x-y-z=34 和 x+y/3=2y-z/4=x+z/2=1_数学解答

x:y=5:3 x:z=7:3 2x-y-z=34 和 x+y/3=2y-z/4=x+z/2=1

人气：454 ℃　时间：2020-06-11 01:21:40

解答

x:y=5:3 y=3x/5
x:z=7:3 z=3x/7
2x-y-z=34 2x-y-z=2x-3x/5-3x/7=34x/35=34 x=35
x=35, y=21, z=15
x+y/3=1 y=3(1-x)
x+z/2=1 z=2(1-x)
2y-z/4=16(1-x)-(1-x)/2=11(1-x)/2=11-x=2/11x=9/11
x=9/11, y=6/11, z=4/11