Hi @gregmat,
The following example in the prepswift algebra video is incorrect.
I think x can be zero.
Assuming x = 0, the equation can be solved like
(2*0 + 3) / (4 - 5*0) = 3 / 4
The original equation is the one on the top left. We know that the denominator cannot equal zero.
12x-15x^2 cannot equal 0, so 3x(4-5x) cannot equal 0. The two values that x cannot be are 0, and 4/5.
You can also try plugging zero into the original equation. (600+90) / (120-1500) = 0/0, which is undefined.
Correct. But suppose we just had
2x + 3 / 4 - 5x
as the expression, and it wasn’t the result of simplifying a complex expression. Then x can be zero, right?
Yes.