C-04-Q079mediumsingle_mcqSimplify 3⋅2n−4⋅2n−22n−2n−1\dfrac{3 \cdot 2^n - 4 \cdot 2^{n-2}}{2^n - 2^{n-1}}2n−2n−13⋅2n−4⋅2n−2 (Example 2):a222b444c111d00