It's 3...
First you add 3 to both sides.(1/3x^2=3)
Then multiply both sides by 3. (x^2=9)
Then take the square root of both sides. (x=+-3)
Finally since it is asking for the positive solution, you can remove the negative sign and so the answer is 3.
The biggest national park of USA is Wrangell- St. Elias National Park And Reserve
The main vent is the main outlet for the magma to escape. Secondary vents are smaller outlets through which magma escapes. The crater is created after an eruption blows the top off the volcano
is about 55 miles at its narrowest point. so around 50 miles would be the answer.