I don't get the image displayed -- without manually taking out the #+RESULTS: line. I'm saying
#+begin_src gnuplot :exports code :file images/test1.png
reset
set title "Putting it All Together"
set xlabel "X"
set xrange [-8:8]
set xtics -8,2,8
set ylabel "Y"
set yrange [-2:70]
set ytics -20,10,70
f(x) = x**2
g(x) = x**3
h(x) = 10*sqrt(abs(x))
plot f(x) w lp lw 1, g(x) w p lw 2, h(x) w l lw 3
#+end_src
#+RESULTS:
[[file:images/test1.png]]
doesn't display the plot image, while. . .
#+begin_src gnuplot :exports code :file images/test1.png
reset
set title "Putting it All Together"
set xlabel "X"
set xrange [-8:8]
set xtics -8,2,8
set ylabel "Y"
set yrange [-2:70]
set ytics -20,10,70
f(x) = x**2
g(x) = x**3
h(x) = 10*sqrt(abs(x))
plot f(x) w lp lw 1, g(x) w p lw 2, h(x) w l lw 3
#+end_src
[[file:images/test1.png]]
. . . does display the plot image:
. . .
<div class="figure">
<p><img src="" alt="test1.png" />
</p>
</div>