The formula for an absolute value equation is:
y = a l x - h l + k
(h , k) is the vertex
In the equation given, y = l 3 - x l + 1 can also be written as y = l x - 3 l + 1
The h is 3 and the k is 1 so the vertex is (3 , 1), this is one point.
The equation is positive so you know it will face up.
Another point can be found by replacing x with 0, y = l 0 - 3 l + 1
y = l - 3 l + 1
y = 3 + 1
y = 4
(0 , 4)
