In multiplying and dividing if there is 2 negatives it is always a positive but if it is 1 negative and a positive it is always a negative. This is only for multiplying and dividing. So the answer is negative 10.
Not sure i remember this but i think radius is like half of the diameter. it’s a line from the center, to a side of the circle. in this situation, line RO would be representing the radius.
