I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.
The function Æ’ is defined by Æ’(x) = (x + 3)(x + 1). the graph of Æ’ in the xy-plane is a parabola. which interval contains the x-coordinate of the vertex of the graph of Æ’?