If x = 3 and y = 5 then which of the following expression has the value ( -8)​

The function ƒ is defined by ƒ(x) = (x + 3)(x + 1). the graph of ƒ in the xy-plane is a parabola. which interval contains the x-coordinate of the vertex of the graph of ƒ?

Ineed in figuring out this problem.

Aline passes through 3,7 and 6,9 what equation represents the line