Subtract 2+b/ab from 3/a

Subtract 2+b/ab from 3/a

Select all of the quadrants that the parabola whose equation is y=√x-4 (principal square root) occupies. i ii iii iv

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

Can someone me and explain..will award brainlest!