X= 14
2(X+4) = 2x+8
3x-6 = 2x+8
-6=2x-3x+8
-14 = -1x
X=14
Answer:

Step-by-step explanation:
step 1
Find the units rate of the first glacier

using proportion

step 2
Find the units rate of the second glacier

using proportion

step 3
Find the difference

I personally use y2-y1 over x2-x1 because it's simple. Plot two y values and two x values. The first ones you plotted are x1 and y1, the others are x2 y2. Now subtract y2-y1 and x2-x1. Afterwards, divide the y value by the x value, that will give you slope.