Element X decays radioactively with a half life of 7 minutes. If there are 120 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 2 grams?

Which expression is equivalent to sq-80

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.