1
Adam's mother is now 42 years old . 7 years ago , she was 5 times as old as Adam . How old is Adam now?
2
Henry spend $30 on transportation and food every day . If the amount spent on food is 4 times that on transportation , find the amount spent on food .
F.1~Mathsmatics Homework~~Fast
2010-10-12 1:37 am
回答 (3)
2010-10-12 2:15 am
1)
Let Adam now is y years old.
5(y-7)=42-7
5(y-7)=35
5y-35=35
5y=35+35
y=70/5
y=14
Adam now is 14 years old.
2)
Let y be the amount on Transporttion
y + 4y = 30
5y=30
y=30/5
y=6
the amount on Transporttion is $6.
the amount spent on food is:
30-6
=24
The mount spent on food is $24
Let Adam now is y years old.
5(y-7)=42-7
5(y-7)=35
5y-35=35
5y=35+35
y=70/5
y=14
Adam now is 14 years old.
2)
Let y be the amount on Transporttion
y + 4y = 30
5y=30
y=30/5
y=6
the amount on Transporttion is $6.
the amount spent on food is:
30-6
=24
The mount spent on food is $24
2010-10-12 2:03 am
1.
Let Adam's current age be x years old.
5(x-7) = 42 -7
5x-35 = 35
5x = 70
x = 14
(therefore) Adam is now 14 years old.
2.
Let the amount spent on food be $y.
y+y/4 = 30
1.25y = 30
y = 24
(therefore) The amount spent on food is $24
Let Adam's current age be x years old.
5(x-7) = 42 -7
5x-35 = 35
5x = 70
x = 14
(therefore) Adam is now 14 years old.
2.
Let the amount spent on food be $y.
y+y/4 = 30
1.25y = 30
y = 24
(therefore) The amount spent on food is $24
2010-10-12 1:52 am
1)(42-7)/2+7
=17.5+7
=24.5
2)30*4
=120
=17.5+7
=24.5
2)30*4
=120
收錄日期: 2021-04-13 17:34:21
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