An isotope has a half life of 102 years. how much of a 22gram sample is left after 250 years?

Find the area of the regular hexagon if a side is 20 cm.

The pyramid shown has a square base that is 24 centimeters on each side. the slant height is 16 centimeters. what is the lateral surface area?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0