Question

The expression below represents the number of bacteria in a petri dish after t hours. Interpret the meaning of the expression.

Answer 1

The answer is B) The initial number of bacteria is 57, and the growth rate is 31% per hour.

The expression shown is an exponential expression.  An exponential expression usually takes the form $ab^{x}$, as this one does.  A represents the initial value, in this case-the initial number of bacteria.  B represents the growth rate.  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!