Question

You can model the entrance to a mine shaft using the equation

Answer 1

Hey there,

You can model the entrance to a mine shaft using the equation
y = − 2 (x + 4)(x − 4), where x and y are measured in feet. The x-axis represents
the ground. Find the width of the entrance at ground level. 

Based by looking on this question above, your correct answer would be . . .

$\boxed{y=8}$ and $\boxed{x=-1}$

Hope this helps.
~Jurgen

Answer 2

y=-1/2 2 (x+4)(x+-4+

-1/2*2 = -1

y=-1(x+4)(x-4)

solving for x

x - -4 and x =4

-4 to 4 = 8 feet

 width = 8 feet