What steps of the equation of the line using point slope formula then using slope intercept form (1,2) with slope of -4/5

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.

Aline passes through the point (–7, 5) and has a slope of 1/2 which is another point that the line passes through?

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2 acellus answer