The answer is B) The initial number of bacteria is 57, and the growth rate is 31% per hour.
The expression shown is an <em>exponential expression</em>. An exponential expression usually takes the form 
, as this one does. A represents the <em>initial value</em>, in this case-the initial number of bacteria. B represents the <em>growth rate</em>. When it is an increasing growth rate, it will begin with 1, because it will have everything it had before, plus the percent increase, the decimal portion. In this case, a=57, and b=0.31.
Hope this makes sense!
Looks like you have to attach a picture. It wont work, because all you did was copy it.
(-27-19=-2x) then you add then you get (-46=-2x) divide by -2 you get 23
so x=23
It is undefined because you can’t have 0 as a denominater
