Observe the figure, then make a table of ordered pairs.
\ \\
\
x \ | \
\
–3 \ | \
\
–2 \ | \
\
–1 \ | \
0 | \1 | \
\
y \ | \
\
–5 \ | \
\
–3 \ | \
\
–1 \ | \
1 | \3 | \
The difference of the x values is 1, and the difference of the y values is 2.
\The difference in y values is twice the difference of x values.
\Then the equation of the function f (x) = y = 2x.
The solution of the equation is y = 2x.