capital(x)=(500-4*x)/7
storage(x)=(400-11*x)/3
land(x)=75-x
f(x)=(x<=0) ? 0 : (x<=8.333) ? capital(x) : (x<=21.875) ? land(x) : (x<=400/11) ? storage(x) : 0
set xrange [-10:50]
set yrange [-10:90]
set samples 500,100
set grid
set xzeroaxis
set yzeroaxis
unset border
plot f(x) with filledcurve, capital(x),storage(x),land(x)
set term svg
set output "farmer0.svg"
replot
set term x11
set output