<span>The surface area of a sphere is equal to [4 x Pi x R^2]. In other words, four multiplied by 3.14 multiplied by the radius squared. If the radius of a sphere is 15 yards, the approximate surface area is [4 x 3.14 x (15x15)] = [12.5 x 225] = [2,812 yd^2]. The surface area of a sphere with radius 15 yd is approximately 2,800 yards.</span>
Answer:
(2a + 1)(a + 3) = 2a² + 7a + 3
Wait, this is simplified because there are no common terms.
Lets say that the two unknown integers are

and

.
We know the following things about

and

:


And, we want to find

.
To solve this, we'll use the expansion of the squared of the sum of any two inegers; this is expressed as:

So, given what we know about the unknown integers, the previous can be written as:

We can easily solve for

:
The answer is 168.
Another approach to solve the problem is, from the two starting equations, compute the values of

and

, which are 12 and 14, and directly compute their product; however, the approach described is more elegant.