數學題!!!方程(答得叻就最佳回答)

如果係
9/a=b
6/a=b+11
6/a-9/a=11
a=-3/11

如果係
a/9=b
a/6=b+11
a/6-a/9=11
a=198

easy la~@@

設某數是ｘ
９／ｘ－６／ｘ>11
(1/x)(9-6)>11
(1/x) (3)>11
1/x>11/3
1/x>3又 2/3
　　　　　ｘ＞3又 2/3
所以某數是大於3又 2/3

設某數是y.
y / 9 = y / 6 - 11
y / 9 + 11 = y / 6
11 = y / 6 - y / 9
11 = 3y / 6 - 2y / 9
11 = ( 3y - 2y ) / 18
11 * 18 = 3y - 2y
198 = y
y =198
.'. 某數是198.

let z be 某數
z/9=y...................................(1)
z/6=y+11..............................(2)

from(2)
z/6-11=y..............................(3)

(1) = (3) = y
z/9 = z/6 - 11 = y
z/9 = (z-66)/6
6z = 9z - 594
6z-9z = -594
-3z = -594
z = 198
所以，某數＝198

check:
198/9=22
198/6=33
33-22=11

設某數為x
x / 9 = x / 6 -11
x / 9 = (x - 66) / 6
6x = 9x - 594
3x = 594
x = 198
所以某數就等於198