Rút gọn biểu thức: A = log2(x3 – x) – log2(x + 1) – log2(x – 1) (x > 1).
Giải thích
Với x > 1, ta có
A = log2(x3 – x) – log2(x + 1) – log2(x – 1)
= log2x3−xx+1−log2x−1
= log2xx2−1x+1x−1
= log2xx−1x+1x+1x−1=log2x.
Với x > 1, ta có
A = log2(x3 – x) – log2(x + 1) – log2(x – 1)
= log2x3−xx+1−log2x−1
= log2xx2−1x+1x−1
= log2xx−1x+1x+1x−1=log2x.