The complete graph of y=f(x), which consists of five-line segments, is shown in red below. (On this graph, the distance between grid lines is 1.) What is the sum of the x-coordinates of all points where f(x) = x+1?
Just draw the line y=x+1 on top of the graph and see where the two graphs cross each other.
Add up the x values of the co-ordinates
Please no one give a full answer