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

3 + (4 + 4) ÷ 4 x 4 - 2²
P: 3 + (8) ÷ 4 x 4 - 2²
E: 3 + 8 ÷ 4 x 4 - 4
MD: 3 + \( \frac{8}{4} \) x 4 - 4
MD: 3 + \( \frac{32}{4} \) - 4
AS: \( \frac{12}{4} \) + \( \frac{32}{4} \) - 4
AS: \( \frac{44}{4} \) - 4
AS: \( \frac{44 - 16}{4} \)
\( \frac{28}{4} \)
7

To fill a 15 gallon tank exactly halfway you'll need 7\(\frac{1}{2}\) gallons of fuel. Each fuel can holds 2\(\frac{1}{2}\) gallons so:

cans = \( \frac{7\frac{1}{2} \text{ gallons}}{2\frac{1}{2} \text{ gallons}} \) = 3

Average speed in miles per hour is the number of miles traveled divided by the number of hours:

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{3}{6} \) x \( \frac{2}{6} \) = \( \frac{3 x 2}{6 x 6} \) = \( \frac{6}{36} \) = \(\frac{1}{6}\)

To multiply terms with radicals, multiply the coefficients and radicands separately:

8\( \sqrt{6} \) x 9\( \sqrt{9} \)
(8 x 9)\( \sqrt{6 \times 9} \)
72\( \sqrt{54} \)

Now we need to simplify the radical:

72\( \sqrt{54} \)
72\( \sqrt{6 \times 9} \)
72\( \sqrt{6 \times 3^2} \)
(72)(3)\( \sqrt{6} \)
216\( \sqrt{6} \)