operations with fractions unit test lesson 12 connexus please help dont even need to give me answers just help in general

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Which expression is equivalent to sq-80

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.