For any single draw,


Drawing a white marble or a gray marble are disjoint events; only one of them can happen. So


Out of 224 draws, you should expect

of the marbles to be either white or gray.
(x-9)(x+7)=0
x-9=0 or x+7=0
x=9 or x=-7
:)
C. negative exponents always go at the bottom
19.5 because 6 minus 5.5 is equal to 0.5 and if you just add 0.5 to 19.5 it will be 19.5