What is the equation of this line in standard form?

The sales totals at macy's food store have increased exponentially over the months. which of these best shows the sales in the first three months?

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.

George writes the mixed number as sum and uses the distributive property 1/2.-2/5=1/2-2+2/5=1/2