Answer:
To answer items such as this, we directly substitute the a + 2 to the all the x's in the function such that,
f(a + 2) = (3 + a + 2) / (a + 2 - 3)
Simplifying the function generated above,
f(a + 2) = (5 + a) / (a - 1)
Https://photomath.net/s/o2P0wN
The answers are that the number can equal -4 or 1.
You can find this by setting the number equal to x.
x^2 (The square of a number) + 3x (three times a number) = 4
x^2 + 3x = 4 ---> subtract 4 from each side
x^2 + 3x - 4 = 0
Then you can factor this to find the answers
(x - 4)(x + 1) = 0
Set both equal to 0 and solve.