The distributive property.
Y=2x-3 has a steeper line because the bigger the slope, the more it goes up on the y-axis for every one spot on the x-axis.
The first one goes up 2 spaces for every one it goes over, and the second one goes up one space for every 5 it goes over
The answer is y= a/3(3+x)
Since 216 is the cube of 6, 64 is the cube of 4 and x^3 is the cube of x, we have

so the expression is the sum of the cubes of 6x and 4