Hello,
The equation of the parabola is
y=k(x-1)²-9
and -6=k(0-1)²-9==>k=3
x-intercepts is:
y=0==> 3(x-1)²-9=0==>(x-1)²=3
==> x=1+√3 or x=1-√3
4 significant figures. All figures are significant because the zeros are in between two significant digits
Answer:

Step-by-step explanation:
1) the common form of the point-slope form is y-y₁=s(x-x₁), where s - the slope, (x₁;y₁) - the point belongs to the required line;
2) if s=2.5; x₁= -5; y₁= -6, then the required equation is:
y+6=2/5(x+5).