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Small math problem
Posted: Wed Jun 12, 2013 8:12 am
by Zanghfei
So I have Math MELS in Friday.
So IF I have.
1. General Form
0 = 5x + y + 5
2. To, Function Form
-y = 5x + 5
(Correct me If I'm wrong.)
3. My Math resolution is
-y / -y = 5x / -1 + 5 / -1
4. My conclusion
y = -5x - 5
Do I do wrong?
(Derp, I know this isn't a Math Forum.)
Re: Small math problem
Posted: Wed Jun 12, 2013 10:22 am
by WaeV
It would be much more straightforward to go from this:
0 = 5x + y + 5
Leave y positive and subtract the other terms:
Code: Select all
0 = 5x + y + 5
-(5x + 5) -(5x + 5)
To get function form but with y positive:
-5x - 5 = y
aka
y = -5x - 5
Re: Small math problem
Posted: Wed Jun 12, 2013 12:08 pm
by Zanghfei
Zanghfei wrote:
2. To, Function Form
-y = 5x + 5
4. My conclusion
y = -5x - 5
I am quite unsure and unconvinced that this really the right answer.
Re: Small math problem
Posted: Fri Jun 14, 2013 4:53 am
by Sparky
If you're looking for positive values, do what you are doing but if you have a negative value, multiply by -1 on both sides:
0 = 5x + y + 5
subtract y on both sides
-y = 5x + 5
negative value to positive value by multiplying both sides by -1:
y = -5x - 5
You can also do the same process with x, but simplifying also:
0 = 5x + y + 5
subtract 5x from both sides
-5x = y + 5
multiply by -1
5x = -y - 5
simplify by dividing by 5
x = (-y/5) - 1
Re: Small math problem
Posted: Thu Jul 18, 2013 1:46 pm
by Zanghfei
Thank Sparky!
But it is to late and I got 69% and it doesn't make sense
Re: Small math problem
Posted: Thu Jul 18, 2013 3:07 pm
by 002
well, if everyone wants to do it.
Here's how I would "solve" it.
0 = 5x + y + 5
y = -(5x + 5) ~ subtract non-y terms
y = -5(x + 1) ~ Factor out 5.
or, to get your answer, you can instead
0 = 5x + y + 5
y = -(5x + 5) ~ subtract non-y terms
y = -5x - 5 ~ Multiply by -1 coefficient
You can use either answer for graphing, as both are probably correct. A factored equation is easier to graph, though.