PLEASE HURRY : A container is 40% filled with liquid. The container holds 1560 gallons of liquid. How many gallons of liquid are needed to fill the container to top?

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.

Rewrite so the subject can be y in the formula d=m-y/y+n

3/4 + p = 1/2? i’m not sure how to solve it