She is wrong because 340 and 304 are different number but she was thinking that the numbers are 340 and 340 not 304.
31 is the answer because you would do 5 x 3 an that's 15 and if it's squared u technically add 15 a second time
Use the slope formula (y2-y1)/(x2-x1)
(0+9)/(4+7)=9/11
Since q is parallel to r the slope will be the same. 9/11 is the slope of line r