Written as a simplified polynomial in standard form, what is the result when (2x+8)^2(2x+8) 2 is subtracted from 8x^2-38x 2 −3?

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.