Given that the original price of the model boat kit is $67.53 and he has a coupon of $25 off if a purchase is $50 or more. Since the purchase is more than $50, we will deduct 25 from 67.53 so the discounted price of the model boat kit would be $42.53. Hope this answers your question.
15*0.07= 1.05 so 7% of 15 is 1.05. we add this to the total so 7% tax is going to be a price of $16.05
ANSWER
to the nearest hundredth.
EXPLANATION
We have the equation,

Which can be rewritten as

The question demands the use of the quadratic formula.
Comparing this to the general quadratic equation;


The quadratic formula is given by;

We now substitute all the values in to the formula;

We simplify to obtain;


We now split the plus or minus sign to obtain;

This implies that;

Or

This will evaluate to;

Hence, the positive solution rounded to the nearest hundredth is

The answer is C.
SA = bh + (s1 + s2 + s3)H
SA = (6.8)(5.1) + (6.8 + 5.1 + 8.5)(2.5) = 85.68