X+a=3/4 I don't know how to solve this and I need someone to help explain it to me.

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

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Jason went to an arcade to play video games. he paid $2 for every 11 tokens he bought. he spent a total of $16 on tokens. which equation can be used to determine,t, the number lf tokens jason bought