The nine clarifies the problem.
5(f - 9) = -3(11 - f) Remove the brackets. Here we have the distributive property in action. We are showing how to remove the common fact outside the brackets so we can solve for the equation.
5f - 5*9 = -3 * 11 - 3*f Combine
5f - 45 = -33 + 3f Add 45 to both sides.
5f - 45 + 45 = - 33+ 45 + 3f Combine
5f = 12 + 3f Subtract 3f from both sides
5f - 3f = 12 + 3f - 3f Combine
2f = 12 Divide by 2
2f/2 = 12/2
f = 6 Answer