To fill a 8 gallon tank exactly halfway you'll need 4 gallons of fuel. Each fuel can holds 2 gallons so:

cans = \( \frac{4 \text{ gallons}}{2 \text{ gallons}} \) = 2

To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [20, 40, 60, 80] making 20 the smallest multiple 4 and 10 share.

Next, convert the fractions so each denominator equals the lowest common multiple:

\( \frac{5 x 5}{4 x 5} \) - \( \frac{7 x 2}{10 x 2} \)

\( \frac{25}{20} \) - \( \frac{14}{20} \)

Now, because the fractions share a common denominator, you can subtract them:

\( \frac{25 - 14}{20} \) = \( \frac{11}{20} \) = \(\frac{5}{9}\)

April scored 84% on the test meaning she earned 84% of the possible points on the test. There were 160 possible points on the test so she earned 160 x 0.84 = 134 points. Each question is worth 2 points so she got \( \frac{134}{2} \) = 67 questions right.

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

\( \frac{10\sqrt{8}}{5\sqrt{2}} \)
\( \frac{10}{5} \) \( \sqrt{\frac{8}{2}} \)
2 \( \sqrt{4} \)

A number in scientific notation has the format 0.000 x 10^exponent. To convert to scientific notation, move the decimal point to the right or the left until the number is a decimal between 1 and 10. The exponent of the 10 is the number of places you moved the decimal point and is positive if you moved the decimal point to the left and negative if you moved it to the right:

0.0002998 in scientific notation is 2.998 x 10^-4