If the tiger has consumed 35 pounds of food in 7 days that's \( \frac{35}{7} \) = 5 pounds of food per day. The tiger needs to consume 70 - 35 = 35 more pounds of food to reach 70 pounds total. At 5 pounds of food per day that's \( \frac{35}{5} \) = 7 more days.

To add 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 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [12, 24, 36, 48, 60] making 12 the smallest multiple 4 and 12 share.

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

\( \frac{6 x 3}{4 x 3} \) + \( \frac{4 x 1}{12 x 1} \)

\( \frac{18}{12} \) + \( \frac{4}{12} \)

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

\( \frac{18 + 4}{12} \) = \( \frac{22}{12} \) = 1\(\frac{5}{6}\)

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:

-9b² + 2b²
(-9 + 2)b²
-7b²

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

Solving for time:

time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{55mi}{55mph} \)
1 hour

To subtract these radicals together their radicands must be the same:

9\( \sqrt{18} \) - 8\( \sqrt{2} \)
9\( \sqrt{9 \times 2} \) - 8\( \sqrt{2} \)
9\( \sqrt{3^2 \times 2} \) - 8\( \sqrt{2} \)
(9)(3)\( \sqrt{2} \) - 8\( \sqrt{2} \)
27\( \sqrt{2} \) - 8\( \sqrt{2} \)

Now that the radicands are identical, you can subtract them: