GCF(24, 30, 42) = 6 I think it is.
Answer: Choice D 
Reason:
Exponential functions have the variable in the exponent.
Choice A is a polynomial, which means we can rule it out. Choice B is a log function, so we can rule it out also.
Choice C is a rational function because it is a ratio of two polynomials. This rules out choice C.
Choice D is the only function with the variable in the exponent. That is assuming you meant to say
instead of 
Check out the picture I've got the full explanations on there
Hope it's clear
The slope is undefined because it is a vertical line on the x axis at 0. Its a straight line going up
Step-by-step explanation:
▪ x - 3 < 3x - 7
▪ x + 4 < 3x
▪ 4 < 2x
▪ 2 < x