Christine scored 93% on the test meaning she earned 93% of the possible points on the test. There were 160 possible points on the test so she earned 160 x 0.93 = 148 points. Each question is worth 2 points so she got \( \frac{148}{2} \) = 74 questions right.

In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 8 workers at the company now and that's enough to staff 2 crews so there are \( \frac{8}{2} \) = 4 workers on a crew. 6 crews are needed for the busy season which, at 4 workers per crew, means that the roofing company will need 6 x 4 = 24 total workers to staff the crews during the busy season. The company already employs 8 workers so they need to add 24 - 8 = 16 new staff for the busy season.

A number with an exponent (b^e) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b¹ = b) and a base with an exponent of 0 equals 1 ( (b⁰ = 1).

To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:

-7y⁶ x 8y³
(-7 x 8)y^{(6 + 3)}
-56y⁹

By buying two shirts, Bob will save $21 x \( \frac{20}{100} \) = \( \frac{$21 x 20}{100} \) = \( \frac{$420}{100} \) = $4.20 on the second shirt.

So, his total cost will be
$21.00 + ($21.00 - $4.20)
$21.00 + $16.80
$37.80