You only show a Part 1, but I see answers available for Part 2 and 3.
I am assuming a, b and c are mean to be part 1, part 2 and part 3 in this answer. Additionally I am assuming x is allowed to be any real number.
So we know
f(x) = 4x+1, g(x) = 3x-7
If (Part 1) f(x) = g(x), then
4x+1 = 3x -7 which means that (subtracting 3x from both sides)
x+1 = -7 which means that (subtracting 1 from both sides)
x = -8.
Note that x is a single value, which is a finite set containing 1 element.
Part 2 f(x) > g(x)
This means that
4x+1 > 3x -7
and we can subtract 3x from both sides
x+1> -7 and subtracting 1 from both sides
x > -8.
Note that -7.1234 is greater than -8, so is 0, so is pi, so is sqrt(2) and so on, there are an infinite number of numbers greater than -8, so the solution set is infinite, and the interval for solutions is (-8,infinity) in interval notation
Finally
f(x) < g(x)
means that
4x+1 < 3x -7
subtracting 3x from both sides
x+1 < -7
subtracting 1 from both sides
x < -8
note that -9, -5pi , -sqrt(134) and so on are all less than -8, so again the solution set is an infinite set of numbers, with x< -8
so in interval notation the solution set is (-infinity, -8)