Plotting Equation with straight line

how do I plot this equation in matlab with a straight line

theta=4 x=8 R=9.2 E=5L=7 F=9 a=3

y=-(theta)*(x)+((R*x^3)/(6*E*L))-((F)/((6)*(E)*(L)))*(x-a)^3;

[Star Strider]

See my Answer to your essentially identical Question in: plotting graph straight line

Answer 1

[Stephan]

fplot