A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.

Use PEMDAS (Parentheses, Exponents, Multipy/Divide, Add/Subtract):

4 + (4 + 2) ÷ 5 x 4 - 5²
P: 4 + (6) ÷ 5 x 4 - 5²
E: 4 + 6 ÷ 5 x 4 - 25
MD: 4 + \( \frac{6}{5} \) x 4 - 25
MD: 4 + \( \frac{24}{5} \) - 25
AS: \( \frac{20}{5} \) + \( \frac{24}{5} \) - 25
AS: \( \frac{44}{5} \) - 25
AS: \( \frac{44 - 125}{5} \)
\( \frac{-81}{5} \)
-16\(\frac{1}{5}\)

By buying two shirts, Bob will save $28 x \( \frac{10}{100} \) = \( \frac{$28 x 10}{100} \) = \( \frac{$280}{100} \) = $2.80 on the second shirt.

So, his total cost will be
$28.00 + ($28.00 - $2.80)
$28.00 + $25.20
$53.20

Monica scored 87% on the test meaning she earned 87% of the possible points on the test. There were 400 possible points on the test so she earned 400 x 0.87 = 348 points. Each question is worth 4 points so she got \( \frac{348}{4} \) = 87 questions right.

A prime number is an integer greater than 1 that has no factors other than 1 and itself. Examples of prime numbers include 2, 3, 5, 7, and 11.