6 3/4 I think is a possible answer
The diameter is equal to 12.
8^6 ÷ 4^3
8^6 = 262,144
4^3 = 64
So, 262,144 ÷ 64 = 4,096.
Done!
Let's simplify step-by-step.
<span><span>12<span>x^2</span></span>+<span>9<span>x^2
</span></span></span>Combine Like Terms:
<span>=<span><span>12<span>x^2</span></span>+<span>9<span>x^2
</span></span></span></span><span>=<span>(<span><span>12<span>x^2</span></span>+<span>9<span>x^2</span></span></span>)
</span></span><span>=<span>21<span>x^<span>2</span></span></span></span>