Atoxic radioactive substance with a density of 7 milligrams per square centimeter is detected in the ventilating ducts of a nuclear processing building that was used 45 years ago. if the half-life is 20 years, what was the density of the substance when it was deposited 45 years ago?

X+ y = k 2x + 3y = k + 1 the point of intersection of the lines has an x-coordinate of a.2k + 1 b.-2k + 1 c.2k - 1

Write an algebraic expression for the word expression the quotient of c and 8

The cross-sectional areas of a right triangular prism and a right cylinder are congruent. the right triangular prism has a height of 6 units, and the right cylinder has a height of 6 units. which conclusion can be made from the given information? the volume of the triangular prism is half the volume of the cylinder. the volume of the triangular prism is twice the volume of the cylinder. the volume of the triangular prism is equal to the volume of the cylinder. the volume of the triangular prism is not equal to the volume of the cylinder.