### Chap 4 Algebra... Let's Talk Algebra

Let's express our daily activities with algebraic statements...

Title: My zZzZzZz... hours

Let m be the number of hours I sleep in on Saturday or Sunday
Let n be the number of hours I sleep in a weekday

Total number of hours I sleep in a week = 2 m + 5 n hours

Think about what you do or encounter everyday... use an algebraic statement to describe it (like what is shown above).

1. Let x be the amount of pocket money I get on weekdays.
Let y be the amount of pocket money I get on weekends.
Total amount of pocket money I get in a week=\$(5x+2y)

2. Let m be the amount of time (mins) i spent plurking weekdays

Let n be the amount of time(mins) i spend plurking on weekends

Total number of hours i spend plurking in a week = 30m + 60n mins

3. Let x be the number of sweets I eat on Saturday or Sunday.
Let y be the number of sweets I eat in a weekday.

Total number of sweets I eat in a week = (2x + 5y) sweets

JJ(:

4. Let p be the number of fruits I eat in on Saturday or Sunday.
Let m be the number of fruits I eat in a weekday.
Total number of fruits i eat in a week = (2p+m) fruits

5. I spent a number of hours mousehunting on weekdays.
I spent b number of hours mousehunting on weekends.
Total number of hours i spent in a week:
5Xa+2Xb=(5A+2B)

Ans: (5a+2B)hours spent on mousehunt

6. Title: My TVs... Hours!!!

Let t be the number of hours I watch TVs on weekdays
Let v be the number of hours I watch TVs on weekends

Total number of hours I watch TVs in a week = 5 t + 2 v hours

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8. Let y be the number of hours I do my homework on weekdays.
Let z be the number of hours I do my homework on weekends.
Total number of hours I do my homework in a week: (5 x y) + (2 x z)

9. Let a be the amount of hours I spend learning on weekdays.
Let b be the amount of hours I spend learning on weekends.

Total Amount of time spent on learning : ( 25a + 3.5b ) hours

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11. Let ƒ be the number of hours used to exercise during the weekdays.

Let † be the number of hours used to exercise during the weekends.

No.of hours used for exercising=(6 x ƒ) + (0.5 x †)
= (6ƒ + 0.5†) hours

12. Let a be the number of hours I play HALO on weekdays.

Let b be the number of hours I play HALO on weekends.

No. of hours I spent playing HALO = (2xa)+(3xb)
= (2a+3b)hours

13. Let x be the number of hours i study on weekdays
Let y be the number of hours i study on weekends

number of hours i spend studying: (5 x X)+(2 x y)=(5x + 2y) hours

14. Let x be the number of minutes I spend reflecting on a weekday.
Let y be the number of minutes I spend reflecting on a weekend.

Number of hours I spend reflecting=(15 x X)+(25 x y)=(5x + 2y) minutes.

15. Title: TALKING! i know its lame..

Let m be the number of hours I TALK on Saturday or Sunday
Let n be the number of hours I TALK on a weekday

Total number of hours I TALK a week = (20 x m)+(22 x n)
= (20m)+(22n)

16. Let h be the amount of time I spend on Runescape on a weekday.

And let m be the amount of time I spend during Runescape on the weekends.

Amount of time I spent on Runescape in a week is -> (2 x h)+(11 x m)
= 2h + 11m

17. Title: number of times i clean up the living room

Let z be the number of times i clean up the living room on weekdays
Let y be the number of times i clean up the living room on weekends

Total number of times i clean up the living room: 5z+2y

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19. Let a be the number of hours I spend on weekdays reading voluntarily

Let b be the number of hours I spend on weekends reading voluntarily

Total number of hours I spend reading voluntarily = (3.5 x a) + (1.5 x b)
= 3.5a + 1.5b

20. Title: Using my mac

Let y be the time i use my mac for school work
Let z be the time i use my mac for personal use

Number of hours i use my mac = (1.5xy) + (2xz) = (1.5y) + (2z)

21. Let y be the time i read my book on weekdays
Let z be the time i read my book on weekends

Total time= (5 x y)+(2 x z)
= 5y + 2z

22. Cheng Nee:
Pls elaborate
Total number of hours i spend plurking in a week = 30m + 60n mins
where do "30" and "60" come from?

23. Zhiqi:
Total number of fruits i eat in a week = (2p+m) fruits
Are you saying that it reflects the number of fruits you eat in the weekend and 1 other day in the weekday? (Hm... no fruits for the 4 other weekdays?

24. Joshua:
Please elaborate what do "25" and "3.5" (in the expression) represent?
Total Amount of time spent on learning : ( 25a + 3.5b ) hours

25. Ming En:
What do "6" and "0.5" represent in this expression?
No.of hours used for exercising
=(6 x ƒ) + (0.5 x †)
= (6ƒ + 0.5†) hours

26. Shamus:
Based on your definition for "a" and "b"
No. of hours I spent playing HALO = (2xa)+(3xb)
= (2a+3b)hours
says that:
You only play HALO 2 out of 5 weekdays, and 3 out of 2 days in the weekend?
Hm... how did you get 3 days out of 2 days (over the weekend)?

27. Grace:
What do "20" and "22" represent here?
(Do the numbers refer to the number of weekdays and days in the weekend?)
Total number of hours I TALK a week = (20 x m)+(22 x n)
= (20m)+(22n)

28. Sher Li:
What do "15" and "25" in the expression mean?
(Do they represent the number of days?)
Number of hours I spend reflecting=(15 x X)+(25 x y)=(5x + 2y) minutes.

Also, how did you "simplify" such that you get 5x + 2y as the final expression?

29. Zhi Chao:
What do "2" and "11" here represent?
Amount of time I spent on Runescape in a week is -> (2 x h)+(11 x m)
= 2h + 11m

30. Joshua (Masterchef):
What do "3.5" and "1.5" represent?
Total number of hours I spend reading voluntarily = (3.5 x a) + (1.5 x b)
= 3.5a + 1.5b

31. Harsh
What do "1.5" and "2" represent in the expression?
Number of hours i use my mac = (1.5xy) + (2xz) = (1.5y) + (2z)

32. The FOLLOWING...
Your Algebraic Stories have not arrived???

- Ziying
- Bryan
- Mayur
- Kai Chek
- Soh Fan

33. let x be the time i spend time watching television on a weekday
let y be the time i spend time watching television on a weekend
how much more time i spend watching on weekends then weekdays = (2y-5x) hours

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35. Let a be the number of hours I play HALO on weekdays.

Let b be the number of hours I play HALO on weekends.

No. of hours I spent playing HALO = (2xa)+(1xb)
= (2a+b)hours

36. Total number of hours I TALK a day = (20 x m)+(22 x n)
= (20m)+(22n)h

20h= weekdays
22h= weekends

sorry i was not precise. :D

37. Let p be the number of fruits I eat in on Saturday or Sunday.
Let m be the number of fruits I eat in a weekday.
Total number of fruits i eat in a week = (2p+5m) fruits

38. Let a be the number of minutes I spend to exercise on a weekday
Let b be the number of minutes I spend to exercise on a weekend

Total number of minutes I take to exercise in a whole week is,

5Xa+2Xb=5a+2b

39. Let ƒ be the number of hours used to exercise during the weekdays.

Let † be the number of hours used to exercise during the weekends.

No.of hours used for exercising
=(6 x ƒ) hours + (0.5 x †) hours
= (6ƒ + 0.5†) hours

Therefore, I spend (6ƒ + 0.5†) hours exercising in a week.

40. Let a be the number of hours I spend on weekdays reading voluntarily

Let b be the number of hours I spend on weekends reading voluntarily

Total number of hours I spend reading voluntarily = (5 x a) hours + (2 x b) hours
= (5a + 2b) hours

41. Title: Using my mac

Let y be the time i use my mac for school work in a day
Let z be the time i use my mac for personal use in a day

Number of hours i use my mac in 1 one week= 7 (y + z)

42. Let q be the number of hours I read on weekdays.
Let p be the number of hour I read on weekends.

Total number of hours I read in a week: (q+p) hours

43. 30 and 60 comes from the total number of minutes i spend on weekdays and weekends. So, 30/5 = 6(mins) on weekdays and 60/2 =30 on weekends.

If i change it, it would be:
Let m be no. of mins i spend plurking on weekdays
Let n be no. of mins i spend plurking on weekends

Total number of mins i spend plurking on weekdays and weekends =30m +60n

44. Mayur:
Interesting expression...
So, are we expecting a positive or negative value?
When will the value of expression become zero?

45. Shamus:

Based on what you've defined,
a is the number of hours you play HALO on weekdays and b is the number of hours you play HALO on weekends

Am I right to interpret that your expression (2a+b)hours means...
In a week, you play HALO 3 days (in total) of which 1 of the days belong to the weekend?

46. Let x be the number of minutes I spend reflecting on a weekday.
Let y be the number of minutes I spend reflecting on a weekend.

Number of minutes I spend reflecting in a week= 5x min + 2y min
= (5x+2y)min