So you follow PEMDAS
So we start with the exponent which is -X^2 so it would turn into X
Now we have X+4=10
We bring the four over and we get X=6
Hope this was helpful and ask questions if you still need help:)
Arc length = radius * central angle (in radians)
central angle (in radians) = arc length / radius
central angle (in radians) = 7.2 / 9
=.8 radians
I believe that the answer is 10 because the first bottle will be exposed to the light 3 times and then the next will be exposed 4 times and then the next 5 and so on so by the tenth bottle it will have been exposed 12 times by the time she drinks it.
The answer is 10
