Hurry no what does x (4 + x) equal ?

Which speed is the fastest (use 1 mile ≈ 1.6 kilometers)? a. 12 miles/hour b. 18 feet/second c. 19 kilometers/hour d. cannot be determined

The vertex of this parabola is at (-2,-3). when the x-value is -1, the y-value is -5. what is the coefficient of the squared expression in the parabola's equation?

The function f(x)= -(x+5)(x+1) is down. what is the range of the function?