25 points and brainliest to whoever answers

  y = x² +6x +8

Step-by-step explanation:

You can write the equation starting from the zeros:

  y = (x -a)(x -b) . . . . . . where the x-intercepts are a=-4, b=-2

  y = (x +4)(x +2)

  y = x² +6x +8

Or, you can start from the vertex form:

  y = a(x -h)² +k . . . . . . . where the vertical scale factor a=1*, and (h, k) = (-3, -1)

  y = (x +3)² -1

  y = x² +6x +9 -1

  y = x² +6x +8

* The vertical scale factor can be found as the difference between the function value at the vertex (-1) and the function value at the point ±1 from the vertex (0). a = 0 -(-1) = 1.

Let L be the length and W be the width. 
"the width of a rectangle is half as long as the length"
W = (1/2)·L
"the rectangle has an area of 18 square feet"
A = L·W = 18
Substitute, 
L·W = 18
L·(1/2)·L = 18
(L²)/2 = 18
L² = 36
L = 6 feet
then W = (1/2) · L
W = (1/2) · 6
W = 3 feet