-30 divided by -5

Question

Its about integers

Answer 1

Say you had two points, P1(1,6) & P2(6,36), on a line and you wanted to know the slope of the line.

 

m = (y2 - y1)/(x2 - x1) = (36 - 6)/(6 - 1) = 30/5

 

Now you want to check with your friend doing the same problem. Right away you notice that your friend labelled the two points, P1(6,36) & P2(1,6). Her calculation was:

 

m = (y2 - y1)/(x2 - x1) = (6 - 36)/(1 - 6) = –30/(–5)

 

Did you or your friend make a mistake? Well, no matter how you label the points the slope of the line should be the same.

 

So –30/(–5) = 30/5. Dividing a negative number by a negative number gives a positive result.

 

 

Answer 2

Both numbers in the quotient are the same sign so the answer will be positive. 

 

-30/-5 = (-1)*30/((-1)*5)=(-1)/(-1)*(30/5)=(30/5)=6.

 

To verify: -5*6=-30.