Help, please the question and thank you

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.

Solve for x: 5/3 x = 20/21 it's fraction. remember to simplify your fraction

Plz 20 points polynomials 1: subtract and simplify (–y^2 – 4y – 8) – (–4y^2 – 6y + 3) 2: multiply and simplify 2x^2 y^3 z^2 · 4xy^4 x^2 3: multiply and simplify (x – 4) (x2 – 5x – 6)