f(x) = (8.0 - x)/2.0
g(x) = (-5.0  - x)/3.0
print "f(4) = ",f(4), " g(4) =" , g(4), "   f(4)-g(4) = ", f(4)-g(4)
print "f(2) = ",f(2), " g(2) =" , g(2), "   f(2)-g(2) = ", f(2)-g(2)
b =  (f(4)-g(4) +  f(2)-g(2))/2.0
print "média das bases =  b =  (f(4)-g(4) +  f(2)-g(2))/2.0  =    ", b
h =  4 - 2
print "altura  = h   =  4 - 2 =  ", h
print "área =   bh =  ", b*h, " conferindo... ", "  49/3.0  = ", 49/3.0