The sum of two adjacent sides is 11 inches, so the long sides are 9 inches. The "unknown number" must be 12.
Given function : 3x−6y=12.
We are given x : −2 0 4.
We need to find the values of y's for x=-2, x=0 and x=4.
Plugging x=-2 in the given equation, we get
3(-2)−6y=12
-6 - 6y = 12.
Adding 6 on both sides, we get
-6+6 - 6y = 12+6
-6y = 18.
Dividing by -6 on both sides, we get
y= -3.
On the same way, plugging x=0.
3(0)−6y=12
-6y =12.
y=-2.
Plugging x=4,
3(4)−6y=12
12 -6y = 12.
Subtracting 12 on both sides.
12-12 -6y = 12-12
-6y=0
y=0.
Therefore,
<h3>x −2 0 4</h3><h3>y -3 -2 0</h3>
Using the quadratic formula, we have:

, so our solutions are

and

.
In terms of pi means to include pi in your answer. In other words, don't use 3.14 or 22/7 for pi.