Knowledge of the principle of multiplication is needed. If you choose from 0 to 9, there are 10 possibilities for the first place in the last two places, and similarly, there are 10 possibilities for the second place.
So 10 * 10 = 100 possibilities.
2. title translation: for all positive numbers x, there is a functional relationship F (x) = x 3-x 2. When x> 1000, which of the following options is closest to the value of f(x)?
When x> is in 1000, f(x) must have at least 9 digits, so the next one is x 3.
choose one