By definition the rate of change of a function is given by:

Or equivalently:

Substituting the values given in the problem we have:

Rewriting we have:
Answer:
the rate of change of the ramp is:
The answer is D. I’m assuming this is surface area so here’s my explanation:) ok so the area of the triangle is 6 (4x3 divided by 2) and when you add the other triangle that’s 12. Ok so we have 12 so far. Then the area of the bottom rectangle is 24 (3x8). Then the area of the side rectangle is 32 (4x8). THEN the top rectangle’s area is 40 (8x5). When you add the numbers up (12+24+32+40) you get 108! And of course dont forget the cm2. ( centimeters squared ). :) I hope this helps
Answer:
the answer can be found in cases like this , the answer is 20