Let's look at the two denominators:
7= 7
4= 4
LCM(7,4)= 4*7= 28
5/7+ 1/4
= (5*4)/ (7*4)+ (1*7)/ (4*7)
= 20/28+ 7/28 (common denominator is 28)
= 27/28
The final answer is 27/28~
The answer for 15 is low pollution
ANSWER
The choice is correct.

EXPLANATION
The equation of a parabola in vertex form is given by:

where (h,k) is vertex of the parabola and 'a' is the leading coefficient of the parabola.
From the given options, the leading coefficient must be a=1.
We also have the vertex of the parabola at (1,2). This implies that h=1 and k=2.
We substitute these values into the formula to get,

The second option is correct.
Answer: 8
Step-by-step explanation:
50% is half and half of 16 is 8.