Question

已知:2X-3y+2z=0,x+4Y-9/2z=0求:X:Z的值.X:y:Z的值.X+2y+X/X+y+Z的值. 已知:

Answer 1

1、

x+4y-9/2z=0

即2x+8y-9z=0 (1)

2x-3y+2z=0 (2)

(1)-(2)

11y-11z=0

y=z

(1)×2+(2)×9

4x+16y-18z+18x-27y+18z=0

22x-11y=0

y=2x

x:y=1:2

所以x:y:z=1:2:2

2、

y=z=2x

(x+2y+z)/(x+y+z)

=(x+4x+2x)/(x+2x+2x)

=7x/5x

=7/5