Make 37.5% into decimal form : Since it is being marked up, add 100% = 1.375
1.375 x 80
1.375
x 80
_________
0000
+11000
_________
110.000
80 marked up by 37.5% is 110.
See attachment although I gather this is not your question. I did the graph(s) for the function,
Answer : B
x^2-9x+14
Lets factor 
We find out two factors whose product is +14 and sum is -9
Two factors are -2 and -7, we split the middle term -9x using -2 and -7

Group first two terms and last two terms
Then factor out GCF from each term



so x-2 is one of the factor