Why negative times negative is positive?

Question

I know that many people would say I don't even know this. But I know it very well that negative × neagtive = positive. But I don't know Why? So kindly give a logical answers.

score 1 · Answer 1 · answered Jun 12 '15 at 06:33

1

Debt is negative. If you take away someones debt, you would be practically giving them positive money.

answered Jun 12 '15 at 06:33

Gappy Hilmore

3,937

http://mathforum.org/dr.math/faq/faq.negxneg.html Related link about the example grdgfgr gave. – Sake Jun 12 '15 at 06:35

score 0 · Answer 2 · answered Jun 12 '15 at 06:37

0

Mathematically, we define $\mathbb{R}$ to be an ordered field, which has this property (proposition 1.18 in baby Rudin). Intuitively, "negative"="opposite", and the opposite of the opposite is the same.

answered Jun 12 '15 at 06:37

Joe Moeller

470

Good explanation! – NeilRoy Jun 12 '15 at 06:56

Why negative times negative is positive?

2 Answers2