Simplifying
7f(5) = 0
Reorder the terms for easier multiplication:
7 * 5f = 0
Multiply 7 * 5
35f = 0
Solving
35f = 0
Solving for variable 'f'.
Move all terms containing f to the left, all other terms to the right.
Divide each side by '35'.
f = 0
Simplifying
f = 0