Select the property of equality used to arrive at the conclusion.
if 1/3x=5, then x=15
a. the multiplication property of equality.
b. the addition property of equality.
c. the subtraction property of equality.

Add 1/7 + -1/7 your answer should be reduced to its smallest form and should not be an improper fraction

Find the cosine function that is represented in the graph.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.