branch$($branch$\_$name, branch$\_$city, assets$)$

customer$($ID$,$ customer$\_$name, customer$\_$street, customer, city$)$

loan$($loan$\_$number, branch$\_$name, amount$)$

borrower$($ID$,$ loan$\_$number$)$

account$($account$\_$number, branch$\_$name, balance$)$

depositor$($ID$,$ account$\_$number$)$

Give an expression in relational algebra for each of the following queries.

a$.$ Find each loan number with a loan amount greater than $$10000.$

b$.$ Find the ID of each depositor who has an account with a balance greater than $$6000.$

c$.$ Find the ID of each depositor who has an account with a balance greater than $$6000$ at the "Uptown" branch.

Please explain steps to arrive at answer.