7w = 87;w = 12 Please help!

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

Let x = a + bi and y = c + di and z = f + gi. which statements are true?

Determine if this is a solution to the system