Please help. It's for a math project and I am a bit confused on which formulas to use. Please show work and explain so I can fully understand. Thank you!

Car Loan on an $84,625car \begin{tabular}{|c|c|} \hline Down Payment \% & 15% \\ \hline Down Payment Amount & $12,693.75 \\ \hline Loan Amount & $71,931.25 \\ \hline Interest Rate (compounded Monthly) & 6% \\ \hline r=0.06 \\ \hline Loan Length & 4 years \\ & n=48 \\ \hline Monthly Payment & $ \\ \hline Total Amount to be repaid & $ \\ \hline \end{tabular} Mortgage Loan on a $670,00o condo \begin{tabular}{|c|c|} \hline Down Payment % & 20% \\ \hline Down Payment Amount & 134,000 \\ \hline Loan Amount & P=$536,000 \\ \hline Interest Rate & 0.675% r= \\ \hline Loan Length \& Number of Payments & 30 years n= \\ \hline Monthly Payment & $ \\ \hline Total Amount to be repaid & $ \\ \hline \end{tabular}