A sample of lead-210 was 20 g when it was formed and its half-life is 22 years. Determine the age 9
of the sample if 2.5 g are left. Explain your reasoning.

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.

The length of a shadow of the building is 36m. the length of the pole, which is perpendicular to the ground, is 1.9m. the length of the pole's shadow is 1.52m. what is the height of the building?