code wont work because of error: 'float' object is not callable

Question

a sample of my code is:

1 a = float(a)
2 y = float(y)
3 x = float(x)
4 f = float(f)
5 g = float(g)
6 t = a(y-x) + f
7 if t != g:   ##!= means not = to