Interesting that only integrals along the 
-axis are suggested when integrating along the 
-axis would be much simpler... Anyway, you have to split the interval of integration into two. The "height" of the region is not uniform over the entire interval.
When 
, we have 
. When 
, we have 
. Then the area we want is given by
which seems to agree with the last option.
Answer: y=-5/4x+7
Step-by-step explanation: You can see, by looking at the graph, that the slope will be negative, so you can eliminate the options with a positive slope. You can take the first point (0,7) and the second point (4,2) and calculate the slope (the change in y divided by the change in x). 7-2 is five, so that gives us our numerator of the slope. 0-4 is -4, so that gives us our denominator. That gives us a slope of -5/4, so the only answer with that slope is the third option, y=-5/4+7. I hope this helps!
Need more info! Sorry bub we can’t help answer
