數學I.Q.題

A/5 = B and B+9 = A
方法一:
step 1] (B+9)/5 = B
step 2] B+9 =B x 5
step 3] 9 = B x 5 - B
step 4] 9 = B(1 x 5 - 1)
step 5] 9 = 4B
step 6] B = 2.25
step 7] 2.25 + 9 = A
step 8] A = 11.25
方法二:
step 1] (A/5) + 9 = A
step 2] A/5 = A-9
step 3] 9 = A-(A/5)
step 4] 9= A( 1 - 1/5)
step 5] 9 = 0.8A
step 6] A = 11.25
step 7] B+9 = 11.25
step 8] B = 11.25 - 9
step 9] B = 2.25





2007-08-03 09:42:50 補充：
下面sophiediao, 仲乜抄我? But, 好野先會俾人抄, so again, thanks for copying my answer.

A和B的答案:
A = 11.25
B = 2.25

應該是A=11.25, B=2.25

A/5 = B and B+9 = A

方法一:

step 1] (B+9)/5 = B  

step 2] B+9 =B x 5

step 3] 9 = B x 5 - B

step 4] 9 = B(1 x 5 - 1)

step 5] 9 = 4B

step 6] B = 2.25

step 7] 2.25 + 9 = A

step 8] A = 11.25

方法二:

step 1] (A/5) + 9 = A

step 2] A/5 = A-9

step 3] 9 = A-(A/5)

step 4] 9= A( 1 - 1/5)

step 5] 9 = 0.8A

step 6] A = 11.25

step 7] B+9 = 11.25

step 8] B = 11.25 - 9

step 9] B = 2.25

A = 11.25
B = 2.25

STEP:

B + 9 / 5 = B

B + 9 = 5B

4B = 9

B = 2.25



B + 9 = A

2.25 + 9 = 11.25

A/5=B & B+9=A
即係(B+9)/5=B
B+9=5B
9=5B-B
9=4B
B=9/4=2.25
因為A=B+9, 即係A=11.25
A=11.25, B=2.25

A = 11.25
B = 2.25