Help i have no idea how to do this i will mark you brainless if you actually try to get it right

Convert 2000 swiss francs to dutch guilders

Sally deposited money into a savings account paying 4% simple interest per year. the first year, she earned $75 in interest. how much interest will she earn during the following year? show your work and explain your reasoning in the space provided below.

What are the solutions of the equation x4 + 6x2 + 5 = 0? use u substitution to solve.