Bill receives 4% commission on sales up to $ 25,000 and 6% commission on additional sales. what commission bill does he get when he sells for $ 80,000?

Bill will receive 4% commission on $25,000, and that will equal $1,000.00 (multiply 25,000 x .04).  You will then subtract the $25,000 from the $80,000, which will result in $55,000.  Multiply the $55,000 by .06 and that will equal $3,300.00.  Add $1,000 plus the $3,300 and you will find his commission is $4,300.00 for the total sale of $80,000.