Sodium 24 has a half life of 15 hours. If there are 800 grams of Sodium 24 initially, how long will it take for 750 grams of Sodium 24 to decay?

Can someone answer this question? : )

Is trapezoid abdc the result of a dilation of trapezoid mnpq by a scale factor of ? why or why not? yes, because ab and cd are each the lengths mn and qp. yes, because sides ab and cd are parallel to sides mn and qp. no, because ab is the length mn but cd is the length qp. no, because sides ab and cd have different slopes from sides mn and qp.

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9