A rectangular section of wilderness will be set aside as a new wildlife refuge. Its dimensions are (5 x 10^5) by (4 x 10^4). What is the area of the land? Write your final answer in scientific notation. Explain how you got your answer.

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of