The clothes dryer would've been $500 originally :)
The lines that Mark drew are perpendicular.
34.95 x 18%= 6.29
34.95-6.29= 28.66
$28.66 is the sale price
Prime factors of 42: 2x7x3
prime factors of 126: 2x3x3x7
prime factors of 210: 7x3x5x2
now we multiply all the factors that they all have in common: 2x3x7 which is 42. So the highest common factor is 42
A is the answer ...........