Let's think about this with our logic.
As x gets really, really, large, only the variable raised to the highest power will be significant. (For example, a billion squared is a billion times larger than just a billion.)
Therefore, 1-2x^2-3x will be almost the same as -2x^2 as x gets really, really, large.
Now, when x is really, really, large in-2x^2, then the answer will be an infinitely small number.
Therefore, as x gets really, really large, we will get closer and closer to -oo
Similarly, as x gets really, really, small, only the variable raised to the highest power will be significant. (For example, a billionth squared is a billion times smaller than just a billionth.)
Therefore, 1-2x^2-3x will be almost the same as -2x^2 as x gets really, really, small.
Now, when x is really, really, small in-2x^2, then the answer will be an infinitely small number.
Therefore, as x gets really, really small, we will get closer and closer to -oo