Find the area plz and thank u

Cara earns a base pay of $1800 per month at a car dealership plus a commission of 6% of her sales. what are caras total earning in a month in which she sells $40000 worth of merchandise

Jose predicted that he would sell 48 umbrellas. he actually sold 72 umbrellas. what are the values of a and b in the table below? round to the nearest tenth if necessary

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?