Which expression is equivalent to 18x12

Areal estate agent earns $32,000 a year plus $1,000 for each apartment he sells. write an equation that shows the relationship between the number of apartments abe sells,n, and the total amount he earns in a year,e. what is the total amount abe would earn from selling 10 apartments in one year

Combine like terms to make a simpler expression 3z+z

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.