Nikki's sister is 7 years less than twice Nikki's age, a. The sum of Nikki's and her sister's ages is 41. Which equation represents this relationship?
A) a+(7-2a)=41
B) a+(2a+7)=41
C) 2a-7=41
D) a=2a-7

Situation: . find the substance's half-life, in days. round your answer to the nearest tenth. a 11 gram sample of a substance that's used to treat thyroid disorders has a k. value of 0.1247. enter the correct answer n - noekt done no - initial mass (at time t = 0) n - mass at timet k a positive constant that depends on the substance itself and on the units used to measure time t= time, in days