1. In a supermarket,the price of an apple is $2.5, and an orange is $3. Alan got $2 left after buying some apples. However, he would need $2 more if he wanted to buy the same number of oranges.Find the number of apples he bought.
2. A girl's age is 2 years more than 1/2 of her mother's age. If the sum of their ages is 62, find their ages.
F.1數學
2006-11-12 6:57 am
回答 (2)
2006-11-12 7:14 am
✔ 最佳答案
1. Let the number of apples be x,2.5x+2=3x-2
4=0.5x
x=8
.*. the number of apples is 8.
2. Let the age of the girl's mother be x,
1/2x+2+x=62
1.5x=60
x=40
.*.the age of the girl's mother is 40, the age of the girl is 22.
參考: refers to my knowledge
2006-11-12 7:09 am
1. Let the number of apples be X
2.5*X+2+2=3*X
0.5X=4
X=8
2. Let the girl's age be X and the mother's age be Y
X-2=1/2*Y ...(1)
X+Y=62 ...(2)
From (1)
Y=2X-4
Sub. into (2)
X+2X-4=62
3X=66
X=22
Y=2*22-4=40
2.5*X+2+2=3*X
0.5X=4
X=8
2. Let the girl's age be X and the mother's age be Y
X-2=1/2*Y ...(1)
X+Y=62 ...(2)
From (1)
Y=2X-4
Sub. into (2)
X+2X-4=62
3X=66
X=22
Y=2*22-4=40
收錄日期: 2021-04-12 21:16:17
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