Well, if y is the notebook cost, well x+y=6.28, x+x+0.70=6.28, 2x=5.58, x=2.79.
The pencil box costs $2.79, while the notebook costs $3.49.
C (third graph, the parabola); To find if it is a function or not draw a vertical line on the graph. If the vertical line could never intercept the figure more than once anywhere on the graph then it is a function.
You need to find the slope
251-248. 3
------------- = --------
2005-1965. 40
The correct answer that I think it is B
