Answer
Nick needs 3 dollars.
Work Step by Step
To solve this, we can say that Andrew needs x dollars, so A=x.
Since Scott needs two more dollars than Andrew, then S=x+2.
Since Nick needs half as much as Andrew, then N=$\frac{1}{2}$x.
Adding A+S+N=17 as they need 17 dollars so we can solve for x.
x+(x+2)+$\frac{1}{2}$x=17
2x+$\frac{1}{2}$x=17-2
$\frac{5}{2}$x=15
5x=30
x=6
So;1
$\frac{1}{2}$x=$\frac{1}{2}$(6)=3
Therefore Nick needs $3.