 In this video, we provide the solution to question number four for the practice exam number one for math 1050 We're given three functions f, g, and h right here, and we're asked to evaluate f minus g at negative one. So the first thing to note here is that since we're trying to compute f minus g We actually don't need the function h whatsoever. So that's just a distractor to us What does f minus g mean? It means we subtract the functions for which there's two options We could subtract The the algebraic formulas f and g and then evaluate a negative one But f minus g at negative one is the same thing as f of negative one minus g of negative one So if you prefer you could evaluate the functions first then subtract their evaluations or we could just do it algebraically The difference first that's the approach I'm going to take So notice if we take f of x minus g of x We're going to end up with 2x plus 1. That's the function for f And then subtract from that 4x plus 2 do make sure that this negative sign is distributed on to both pieces You're gonna get 2x minus 4x, which is a negative 2x and you're gonna get 1 minus 2, which is a negative 1 there So this is f minus g. So if we want to do f minus g Evaluate a negative 1 we plug negative 1 into this value here negative 2 times negative 1 minus 1 We're gonna get positive 2 minus 1 and so we see that the value would be 1 hence the correct choice is b