(a-1)² - 8(a² - 1)/(a+1)≤0
(a-1)² - 8(a - 1)≤0
(a-1)² - 8(a - 1)≤0
(a-1)(a-9)≤0
(a-1)≤0,(a-9)≥0 ,a≤1,a≥9(舍去)
(a-1)≥0,(a-9)≤0 ,1≤ a≤9
所以(a-1)² - 8(a² - 1)/(a+1)≤0的解集为1≤ a≤9
(a-1)² - 8(a² - 1)/(a+1)≤0
(a-1)² - 8(a - 1)≤0
(a-1)² - 8(a - 1)≤0
(a-1)(a-9)≤0
(a-1)≤0,(a-9)≥0 ,a≤1,a≥9(舍去)
(a-1)≥0,(a-9)≤0 ,1≤ a≤9
所以(a-1)² - 8(a² - 1)/(a+1)≤0的解集为1≤ a≤9