解方程(文字題)(英文)

1)Ann had $100. She used part of her money to buy 7 ceramic cats ,
in which 3 of them are more expensive than the rest by $3 .
If she had $7 left how much do the two types of ceramic cat cost?
Let $x be the cheaper types of ceramic cat cost.
$x+3 be the more expensive type of ceramic cat cost.
4x+3(x+3)=93
4x+3x+9=93
7x=84
x=12
∵the cheaper types of ceramic cat cost $12
the more expensive type of ceramic cat cost $12+$3 =$15

2)The cost of tea A is $30 per kg , the cost of tea B is $20 per kg.
If w kg of tea A and (w+1) kg of tea B are mixed together ,
and the cost of the mixed tea is $ 24 per kg . Find w .
[30w+20(w+1)]/2w+1=24
50w+20/2w+1=24
50w+20=48w+24
2w=4
w=2

3)Ann had a bag of glass beads . She used half of the beads to make a
necklace . She and her sister then use 1/6 and 1/7 of the beads
respectively to make two bracelets. If there are 16 glass beads left ,
find the original number of glass beads.
Let x be the original number of glass beads.
(1- 1/2 - 1/6 -1/7)x= 16
(1/2 - 1/6 -1/7)x=16
(1/3-1/7)x=16
4/21 x =16
x=84

4)In the diagram , a mouse at point A runs due east along one side of
the rectangle. At the same time , a cat at point A runs due south
along another side of the rectangle. Finally , they meet at point C ,
where BC = 60cm. Given that the speed of the mouse is 11/14
times of that of the cat , find the perimeter of the rectangle in
metre .
In the diagram???你都冇圖- -

2009-07-21 17:22:59 補充：
let 2x cm be vthe perimeter of the rectangle,
x-11x/14=60
3x/14=60
3x=840
x=280
∵the perimeter of the rectangle is 5.6 m,,

2009-07-21 17:32:41 補充：
寫錯左

2009-07-21 17:35:58 補充：
let 2x cm be vthe perimeter of the rectangle,
11(x+60)/14=x-60
11x+660=14(x-60)
11x+660=14x-840
1500=3x
x=500
the perimeter of the rectangle is 10 m,,

2009-07-23 13:56:11 補充：
let 2x cm be vthe perimeter of the rectangle,
11(x+60)/14=x-60
11x+660=14(x-60)
11x+660=14x-840
1500=3x
x=500
the perimeter of the rectangle is 10 m

I know Q3 only

Let be n

(1- 1/2 - 1/6 -1/7)n= 16
4/21 n =16
n=84
The original number of glass beads is 84