A line segment begins at $(1, 3)$. It is 5 units long and ends at the point $(4, x)$ and $x > 0$. What is the value of $x$?
distance formula
(x1-x2)^2 + (y1-y2)^2 = d^2
(4-1)^2 + ( x-3)^2 = 5^2
9 + (x-3)^2 = 25
(x-3)^2 = 16
x-3 = 4
x = 7
+36915 
