What do i need to multiply by to decrease by 42%?

A50% increase followed by 33 1/2% decrease

Peter applied to an accounting firm and a consulting firm. he knows that 30% of similarly qualified applicants receive job offers from the accounting firm, while only 20% of similarly qualified applicants receive job offers from the consulting firm. assume that receiving an offer from one firm is independent of receiving an offer from the other. what is the probability that both firms offer peter a job?

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*