I just need to know how 45 divided by -0,9 is -50? someone please explain so I understand.
Thx

45 / ( -0.9 ) = - 45 / 0.9 = - 450 / 9 = - 50

yes its 50
0,9*50=45

this.

Simple way to think about it is this way because dividing by a fraction is simply multiplying by the reciprocal.

45 / -0.9 = 45 / (-9/10) = 45 * (-10/9) = -450/9 = -50

Since you asked for a bit more of an explanation via PM explaining that English is not your first language I'm going to try to explain this as clearly as possible.

45 divided by -0.9

First Step I did was convert -0.9 to a fraction which is -9/10

Thus now we have 45 divided by -9/10

But by the rules of mathematics in order to divide by fractions you simply multiple by the reciprocal (which is b/a if our fraction is a/b, ie. 3/4 is the reciprocal of 4/3)

Now we have 45 * (-10/9) (which by the rules of fractions we simply multiply numerator by numerator and denominator by each other)

Thus we have 45 * -10 in our numerator
Thus we have 1 * 9 in our denominator

Thus -450 / 9 = -50.