120
70+50=120
180-120=60
180-60=120
As you increase the subintervals the area will be closer and closer to the real value. In other words your approximation gets better.
As you increase the intervals, there will be more rectanagles and the added area of these rectangles are converging towards the actual area under the curve.
Answer:
Step-by-step explanation:
It is a solution because if you plug in 84 for b you get 84/12 = 7
