The easiest way to answer any question like this is to first put your equation in the simplest form 'y = mx + b'
So in this case, f(x) = 3/4(10) - x simplifies to f(x) = 7.5 -x which reordered becomes f(x) = -x + 7.5
So if you imagine this on a graph, you'll have a point on the y axis at 7.5. Then there is a line from there at a slope of -1. So you'll have a point at (0,7.5), (1, 6.5) ... (7.5,0). Now flipping this over the x axis is easy enough. Your first point intercepting the y axis is at -7.5. Then you'll have a line going up at a slope of +1. So your new equation will simply be g(x) = x-7.5. Now simply plug any coordinate in for g(x) and x to see if the equation is true. For example, let's try (1,-6.5). So -6.5 = 1-7.5. ---> -6.5 = -6.5. So (1, -6.5) is a point on g(x)!
