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:

\( \frac{2 x 3}{4 x 3} \) + \( \frac{3 x 1}{12 x 1} \)

\( \frac{6}{12} \) + \( \frac{3}{12} \)

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

\( \frac{6 + 3}{12} \) = \( \frac{9}{12} \) = \(\frac{3}{4}\)

If the tiger has consumed 42 pounds of food in 7 days that's \( \frac{42}{7} \) = 6 pounds of food per day. The tiger needs to consume 66 - 42 = 24 more pounds of food to reach 66 pounds total. At 6 pounds of food per day that's \( \frac{24}{6} \) = 4 more days.

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 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80]. The first few multiples they share are [8, 16, 24, 32, 40] making 8 the smallest multiple 4 and 8 share.

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

\( \frac{3 x 2}{4 x 2} \) - \( \frac{2 x 1}{8 x 1} \)

\( \frac{6}{8} \) - \( \frac{2}{8} \)

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

\( \frac{6 - 2}{8} \) = \( \frac{4}{8} \) = \(\frac{1}{2}\)

By buying two shirts, Frank will save $33 x \( \frac{30}{100} \) = \( \frac{$33 x 30}{100} \) = \( \frac{$990}{100} \) = $9.90 on the second shirt.

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

\( \frac{6\sqrt{9}}{3\sqrt{3}} \)
\( \frac{6}{3} \) \( \sqrt{\frac{9}{3}} \)
2 \( \sqrt{3} \)