Answer:
The product of a non-zero rational number and an irrational number is irrational.
He got 16 questions right (5x16=80) and 10 wrong (8x10=80) He got paid $80 but also had to pay $80.
$720 * .06 = 43.2
He will make $43.20 more each week.
You can check your factoring by multiplying them all out to see if you get the original expression. If you do, your factoring is correct; otherwise, you might want to try again