![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Observe the figure, then make a table of ordered pairs.
\| \
x \ | \
\
–4 \ | \
\
–3 \ | \
\
–2 \ | \
\
–1 \ | \
0 | \1 | \2 | \3 | \4 | \
| \
y \ | \
\
–4 \ | \
\
–3 \ | \
\
–2 \ | \
\
–1 \ | \
0 | \1 | \2 | \3 | \4 | \
The difference of the x values is 1, and the difference of the y values is 1.
\The difference in y values is once the difference of x values.
\Then the equation of the function f (x) = y = x.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The solution of the equation is y = x.