A newly discovered radioactive isotope has a half-life of 2 minutes. Scientists isolated a sample of this isotope and measured its initial mass. After 10 minutes, 12.5 g of the isotope was left. What was the initial mass? need the answer asap! thanks

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2

Jacob is graphing the line represented by the equation  −6x−5y=12.−6x−5y=12.  he first plots the  x-x-  and  y-interceptsy-intercepts  as follows.    which statement is correct regarding the intercepts on the graph?