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

3\( \sqrt{63} \) - 8\( \sqrt{7} \)
3\( \sqrt{9 \times 7} \) - 8\( \sqrt{7} \)
3\( \sqrt{3^2 \times 7} \) - 8\( \sqrt{7} \)
(3)(3)\( \sqrt{7} \) - 8\( \sqrt{7} \)
9\( \sqrt{7} \) - 8\( \sqrt{7} \)

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

The area of a circle is given by the formula A = πr² where r is the radius of the circle. The radius of a circle is its diameter divided by two so A = π(\( \frac{d}{2} \))². If the diameter of the logo increases by 75% the radius (and, consequently, the total area) increases by \( \frac{75\text{%}}{2} \) = 37\(\frac{1}{2}\)%

If the tiger has consumed 104 pounds of food in 8 days that's \( \frac{104}{8} \) = 13 pounds of food per day. The tiger needs to consume 195 - 104 = 91 more pounds of food to reach 195 pounds total. At 13 pounds of food per day that's \( \frac{91}{13} \) = 7 more days.

The greatest common factor (GCF) is the greatest factor that divides two integers.

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