At some moment in time, a culture of bacteria contains 100 bacteria. After one hour, there are 300 bacteria, and after 2 hours, there are 900 bacteria in the culture. The bacteria will continue to grow at
the same rate if the conditions are favorable. Which of the following equations can be used to find
the number of bacteria, b, after t hours?
a) b = 100.36
b) b = 100 - 320
c) b = 100-31/2
d) b=100.34

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?