B) b*1.13
1) Since the College textbook's price has been raised up 13%, then we can write:
b(1 +0.13)
b(1.13)
Plugging b = $197 we have:
197(1 +0.13)
197 (1.13)
$222.61
2) So the factor that expresses that difference (13% up) is 1.13
For 1 is equivalent to 100% and 0.13 to 13%
3) Hence, the answer is b* 1.13 calling b that $197.