It is known that x minus 1 / x = 3. Find the square of x plus 1 / 2 of X The square of x plus 5x plus 1 equals 0. Find the square of X and the square of X

It is known that x minus 1 / x = 3. Find the square of x plus 1 / 2 of X The square of x plus 5x plus 1 equals 0. Find the square of X and the square of X

（x-1/x）^2=3^2
x^2-2+1/x^2=9
x^2+1/x^2=11

① Given the set a = {x | x2-x-6 ＜ 0}, B = {x | x2 + 2x-8 ＞ 0}, find a ∩ B. ② if the solution set of inequality - 12x2 + 2x ＞ MX about X is {x | 0 ＜ x ＜ 2}, find the value of M

① For set a, from x2-x-6 ＜ 0, the solution is - 2 ＜ x ＜ 3}; for set B, from x2 + 2x-8 ＞ 0, the solution is x ＞ 2, or X ＜ - 4, B = {x | 2 ＜ x, or X ＜ - 4}; a ∩ B = {x | 2 ＜ x ＜ 3}

The solution set of inequality MX ^ 2 + 2x + 4 > 0 is {- 1}

Because the solution is {- 1