Discontinuities in functions are apparent "holes" in a function where no output value (f(x) also known as y) exists for a particular input value (x).
In problems like yours, where there is a polynomial in the numerator (x + 7) and another polynomial in the denominator (x^2 - 49),...

If it helps at all, the reason you can re-order the terms in the problem is because you can think of subtraction as adding negative numbers:
9x + 2 - 5x - 3 = 9x + 2 + (-5x) + (-3)
Because of the commutative property of addition, we can re-order these terms in...

Here is a method for the problem
1. Find the total area (the school) by converting 1 kilometer into meters and multiplying that by 800 meters. This should give you the total area (the school) in square-meters.
2. Subtract the area of 960 square-meters (the garden) that you don't...