Let us evaluate each pair of expressions one at a time.
8. (n²+4) - n² and 4n.
(n²+4) - n² = n²+ 4 - n² = 4 which is not equal to 4n.
NOT EQUIVALENT
9. 3x + 5 and 2(x + 3)
2(x + 3) = 2x + 6 which is not equal to 3x + 5.
NOT EQUIVALENT
10. 15 - 6x and 15(1 - 6x)
15(1 - 6x) = 15 - 90x which is not equal to 15 - 6x
NOT EQUVALENT
11. (y + y + 2 + y) + 3y and 6y + 2
(y +y +2 + y) + 3y = y+y+y +2 + 3y = 3y + 2 + 3y = 6y + 2.
It matches the other expression.
EQUIVALENT
12. 8y - 3 + 10y and 3(6 - 1)
8y - 3 + 10y = 8y + 10y - 3 = 18y - 3
3(6 - 1) = 3(5) = 15
The two expressions do not match.
NOT EQUIVALENT.
Answer: Only the expressions in number 11 are equivalent.
I'm assuming the given log equation is 
If so, then the exponential form is 
This is because the general form
transforms into 
For both equations, the 'b' is the base.
The domain is the value of x, the range is the value of y.
A parabola opens infinitely to the right and left, so x can be any number, the domain is all real numbers
Vertically, however, a parabola opens only one way, either upward or downward. when it opens upward from a a certain level, say, the lower point (the vertex) has a y coordinate of 2, we say the range is all real numbers larger than or equal to 2, or y≥2. When it opens downward, we say the range is all real numbers smaller or equal to 2, y≤2