Thread: Grade 8 Algebra

I have these Algebra Problems that I just do not understand. So far I understand the whole idea of what algebra is and variables, but I do not understand these problems.

http://i52.tinypic.com/2md3xjo.jpg

http://i53.tinypic.com/245zu6p.jpg

Your help would be greatly appreciated.

Thanks~!

taking the cooking time example:

"15 minutes + 35 minutes per kilogram"

This would be
for 1kg: t = 15 + (35*1)
for 2kg: t = 15 + (35*2)
for 3kg: t = 15 + (35*3)
for 4kg: t = 15 + (35*3)
...
for 10kg: t = 15 + (35*10)
...

What if i told you the number of kilograms was "x" insead of specifying the number
for xkg: t = 15 + (35*x)


The same approach may help on the other question

Originally Posted by SpringFan25

taking the cooking time example:

"15 minutes + 35 minutes per kilogram"

This would be
for 1kg: t = 15 + (35*1)
for 2kg: t = 15 + (35*2)
for 3kg: t = 15 + (35*3)
for 4kg: t = 15 + (35*3)
...
for 10kg: t = 15 + (35*10)
...

What if i told you the number of kilograms was "x" insead of specifying the number
for xkg: t = 15 + (35*x)


The same approach may help on the other question

Thanks!

So if the variable for kg was m I would have to go : m kg: t= 15+ (35x2)
That would mean that the amount of kilo's is two. Right?

The first one asks you to fill out a table showing how much remains to be paid off you are told they are 1000- 200, 1000- 200(2), 1000- 200(3), etc. What are those amounts? After the week 1 he still owes 1000- 200(1), after week 2 he still owes 1000- 200(2), after week 3 he still owes 1000- 200(3), after week 4 he still owes 1000- 2(4), etc. How much does he still owe after week n? Do you see where the "week number" fit into each of those? Replace that with n.

The second gives a recipe that says you must roast for 35 minutes for each kilogram plus an additional 15 minutes. If your roast weighed 2 kg, you roast it for 35 minutes for each kg: 2(35)= 70 minutes, then and additional 15 minutes: 70+ 15= 85 minutes. Suppose your roast weight 3 kg. How long would you cook it? What if it were four kg.? Think about what you did there. What if it were "x" kg.?

Thanks!

So if the variable for kg was m I would have to go : m kg: t= 15+ (35x2)
That would mean that the amount of kilo's is two. Right?

yes, the formula for 2kg would be
t=15 + (35*2)

the formula for m kilos would be
t = 15 + (35*m)

Originally Posted by HallsofIvy

The first one asks you to fill out a table showing how much remains to be paid off you are told they are 1000- 200, 1000- 200(2), 1000- 200(3), etc. What are those amounts? After the week 1 he still owes 1000- 200(1), after week 2 he still owes 1000- 200(2), after week 3 he still owes 1000- 200(3), after week 4 he still owes 1000- 2(4), etc. How much does he still owe after week n? Do you see where the "week number" fit into each of those? Replace that with n.

The second gives a recipe that says you must roast for 35 minutes for each kilogram plus an additional 15 minutes. If your roast weighed 2 kg, you roast it for 35 minutes for each kg: 2(35)= 70 minutes, then and additional 15 minutes: 70+ 15= 85 minutes. Suppose your roast weight 3 kg. How long would you cook it? What if it were four kg.? Think about what you did there. What if it were "x" kg.?

Thank you halls of Ivy.
I understand the second explanation, but I do not understand the 1st.
Must I go for month 4 : 80 000- (20 000 x t)

If so, what is that (A) for?

THANKS!

Originally Posted by JesseElFantasma

Thank you halls of Ivy.
I understand the second explanation, but I do not understand the 1st.
Must I go for month 4 : 80 000- (20 000 x t)

If so, what is that (A) for?

THANKS!

What (A) I dont see any A,and i dont see the numbers used by HoI either and I dont see any 20,000 so am a bit confused

original loan 80,000
repayment is 2,000 per month so at end of
month 1 its 80,000 - 2000= 78,000
Month 2 its 80,000 - 2,000 - 2,000 or 80,000 - (2,000 * 2)

Month n its 80,000 - (2,000*n)

Originally Posted by Carlow52

What (A) I dont see any A,and i dont see the numbers used by HoI either and I dont see any 20,000 so am a bit confused

original loan 80,000
repayment is 2,000 per month so at end of
month 1 its 80,000 - 2000= 78,000
Month 2 its 80,000 - 2,000 - 2,000 or 80,000 - (2,000 * 2)

Month n its 80,000 - (2,000*n)

Thank you
And about the (A)

In the description it says: relating the amount that he still owes (A) after any number of months (t)

Grand, the old mince pies are not the Mae West so I missed the A and t in the .jpg No reply needed