it states it has been 7 weeks. 0.2 x 7 is 1.4. That means they started with 2.4 + 1.4 meters thick of ice sheet, which is 3.8, which is the number they started with. So, b = 3.8 and it says it melts 0.2 so it's a negative, which is -0.2 as slope. So, y = -0.2x + 3.8
