What is the vertex of the parabola given by the equation y = x2 + 4? a. (2, 8) b. (-2, 8) c. (0, 4) d. (4, 0) e. (0, 0)

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g