數學題....解方程 2條

1. 設蘋果總數量為x
青蘋果佔7分之3，則紅蘋果.佔7分之4，即4/7x
紅蘋果有8個，即 4/7x = 8

4/7x = 8
4x = 56
x = 16
蘋果總數量是16個

2.設曲奇餅總數為y
朱古力味佔4分之1，即1/4y
牛油味的佔3分之1，即1/3y
兩款曲奇餅共有14塊，即1/3y + 1/4y = 14

1/3y + 1/4y = 14
1/3y(12) + 1/4y (12) = 14(12)
4y + 3y = 168
7y=168y
y=24

曲奇餅共24塊

1. 設蘋果總數量為x
青蘋果佔7分之3，則紅蘋果.佔7分之4，即4/7x
紅蘋果有8個，即 4/7x = 8

4/7x = 8
4x = 56
x = 16
蘋果總數量是16個

2.設曲奇餅總數為y
朱古力味佔4分之1，即1/4y
牛油味的佔3分之1，即1/3y
兩款曲奇餅共有14塊，即1/3y + 1/4y = 14

1/3y + 1/4y = 14
1/3y(12) + 1/4y (12) = 14(12)
4y + 3y = 168
7y=168y
y=24

曲奇餅共24塊

1. green apple = x total= y
x+8=y 1
3/7y=x 2
plug 3/7y from equation 2 into the x from equation 1:
3/7y+8=y
solve for y:
3/7y - y= -8
- 4/7y = -8
y = 14

plug 14 into x from equation 1:
14+8=y
solve for y:
14+8=y
y=22

2. total = x
1/4x + 1/3x = 14
7/12x=14
x= 24

1)蘋果=8/(1-3/7)=14

2)設x是罐曲奇餅總數

x/4+x/3=14
7x/12=14
x=24

2007-05-12 12:29:46 補充：
cookie97
網友的係第一絛的公式是正確,但最後計錯左

1
8 / (4/7)= 56/4 =14

2

1/4 + 1/3 = 7/12

14 / ( 7/12)= 24