The number of bacteria in a culture is increasing according to the law of exponential growth. after 9 hours there are 125 bacteria, and after 21 hours there are 1000 bacteria. (a) how many bacteria were there after 19 hours? (b) about how long does it take for this population to double? check your proposed doubling time by walk-through.

Which situation could best be represented by this linear equation? 24x + 38y = 520 > if x represents the number of bracelets and y represents the number of rings, there were 24 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets and y represents the number of rings, there were 38 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets sold at $24 each and y represents the number of rings sold at $38 each, the total sales were $520 if x represents the number of bracelets and y represents the number of rings, there were 520 bracelets and rings sold. bracelets were $24, and rings were $38. e