-5/5x-1/9x=-102what is the answer for this question

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.

Erik buys 2.5 pounds of cashews. if each pound of cashews costs $7.70, how much will he pay for the cashews?

20 points plus brainliest andwer plus my hover hoard im v desperate ! evaluate the polynomial for x=-2 in the equation -3x^3+7x^2-7x-1 (simplify your answer)