Expert: Richard J. Raridon - 2/27/2010

Question
QUESTION: Hello!
I'm an idiot so I need help on these simple equations! haha
Alright, -1 - 5    -6  
        --- --- = ---
         7 -(-3)  10  

How is this equation so because I thought when subtracting negative and positive numbers; you change the  minus sign to an addition sign and subtract the smaller number from the larger number then give the answer the sign of the larger number?

This other equation is pretty much like the other one but it confuses me as well;
-1/2 - 1/2 = -2/2,  I thought -1 - 1 cancel each other out?
In -1/2; does this mean just the "1" is negative or the whole fraction(both numbers) is negative?

Thank you.

ANSWER: -1/7 -5/[-(-3)] = -1/7 -5/3 = -38/21, not -6/10
-1 -1 does not cancel each other out, -1/2 -1/2 = -1
-1/2 means -(1/2) and applies to the whole fraction.  

---------- FOLLOW-UP ----------

QUESTION: I was actually trying to find the "slope" of the line that passes through the points: (-3, 5) and (7, -1).

Doesn't -2/2 equal -1, anyway?
I was trying to find slope of the line that passes through the points: (1/2, 1/2) and (-1/2, -1/2). I was confused with -1 + 1, they cancel each out.

I should have pointed out that I was working with linear equations.

I just need to pay more attention to what I'm doing

Do you have any general tips/tricks on working with algebraic equations?

Thank you.

I'm not trying to cheat on my homework or anything like that, I really want to learn this and master it.

Answer
the slope passing through two points is given by (y2-y1)/(x2-x1) so you have
(5+1)/(-3-7) = 6/-10 = -3/5 which you had listed but didn't explain what you were trying to get.
yes, -2/2 = -1
the slope of the line through (1/2,1/2) and (-1/2,-1/2) = 1
I don't have any general tips but I'm willing to help with other questions occasionally.