We are learning about inequalities. I originally assumed it would be the same as equations, except with a different sign. And so far, it has been - except for this.
Take the simple inequality:
−5m>25 To solve it, we divide by −5 on both sides, as expected.
m>−5.
But, I have been told that now we have to flip the inequality sign because we divided by a negative (and this also applies to multiplying negatives).
m<−5
And this does work. Plug in any value less than −5 and it does turn out to be more than 25, but why?
Mathematically, why do we flip the sign here?
