If 2/(a - 1) = 4/y and y=0 where a=1 , what is y in terms of? Not sure how to write this on here but here's the picture

Idont understand math at all! : o( use this scenario to answer the remaining questions: brenton purchased a new bedroom set for $4,500.00. he lives in arizona and pays a 8.75% sales tax. if he made a 50% down payment and financed the rest, what amount did he finance? what is the total sales tax brenton will pay? enter your answer in currency format, round to the nearest cent. what was brenton's total amount financed? enter your answer in currency format, round to the nearest cent.

Combine the information in the problem and the chart using the average balance method to solve the problem.

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.