1. solve sqrt (11-x) = sqrt(x-7)

choices are 6,7,8 or9
I think according to my calcs the answer is (9)

The range of f(x) = sqrt(3x-6) - 2
answers would be y<= (-2)
y>= (-2)
y> (-2)
y<=(2)

I think the answer is y <= -2, correct

I don't get this one at all:
Solve -12 = -6sqrt(x+4)
answers are
-1
0
1
2
Do I take both sides to the power of 6 so I can get rid of the sqrt sign, I think?

1 yes

2. How can it be less than -2. sqrt starts at zero, so the range must start at -2 and get greater.
3. divide both sides by -6

2=sqrt(x+4)
square both sides.
4=(x+4)
x=0