Answer:
last option is correct
Step-by-step explanation:

Answer:
1. AB ~= DF
2. Definition of Congruent
3. Reflexive Property of Congruency
4 BD=BD
6. AB+BD=AD; DF+BD=BF
7. Substitution Property of Equality
8. Definition of Congruent
Step-by-step explanation:
1. The given always goes first, and that's the first reason, so AB ~= DF must be the first statement (that should be the congruency symbol).
2. The definition of congruent is that if they are congruent then they are equal. Since that statement made two congruent lines equal, it must be the definition.
3. The reflexive property means something is congruent to itself, and BDis BD, therefore it is the reflexive property.
4. Remember if something is congruent then it is equal.
6. The segment addition postulate states that if we are given two points on a line segment, then AB+AC=AC.
7. In this statement AD was substituted for DF+BD. This can be done because of AB=DF and BD=BD as aforementioned.
8. If two things are congruent then they are equal by definition of congruency.
Answer:
The concentration of a drug in an organ at any time t (in seconds) is given by s 0.25t - 15(1 - e-t/60) if osts 20 | 15e-t/60 – 10e-(t - 20)/60 if t> 20 where c(t) is measured in milligrams per cubic centimeter (mg/cm3). (a) What is the initial concentration of the drug in the organ? 0 mg/cm3 (b) What is the concentration of the drug in the organ after 14 sec? (Round your answer to three decimal places.) x mg/cm3 38 (c) What is the concentration of the drug in the organ after 40 sec? (Round your answer to three decimal places.) mg/cm3 Need Help? | Read It
A binomial squared is written like

So, we have 
So, we want to complete the square 
We can add and subtract 9 to write
