Write the sum as a product. simplify the product. (-2)+(-2)+(-2)+(-2)
a. 4 (-2); -8
b. 5 (-2); -10
c. (-2) + (-2) +(-2)+ (-2); -6
d. 2(-2)+2(-2); 10

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