Question

已知X/2=Y/3=Z/5,且2X+Y-Z=4,求多项式X-3Y+2Z

Answer 1

因为 X/2=Y/3=Z/5
所以 Y=3/2X
Z=5/2X
将Y,Z代入，得：2X+3/2X-5/2x=4
所以，X=4
那么，X-3Y+2Z=X-9/2X+5X=3/2X=6

Answer 2

可以设X\2为K
2K=X
3K=X
5K=Z
带进2X+Y-Z=4去就可以算出K的值
K=2
多项式解出原式可得3K
所以多项式为6

Answer 3

由x／2=y/3=z/5知2x=4y/3 z=5y/3 所以2x+y-z=4y/3+y-5y/3=2y/3=4 所以y=6
x=4 z=8 x-3y+2z=4-18+20=6

Answer 4

X/2=Y/3=Z/5=k
x=2k,y=3k,z=5k
代入2X+Y-Z=4
4k+3k-5k=4
k=2
X-3Y+2Z=2k-9k+10k=3k=6