20 shares at 10 1/2 (or 10.5) = 20 * 10.5 = 210
20 shares at 11 1/4 (or 11.25) = 20 * 11.25 = 225
so the profit made would be : 225 - 210 = $ 15 <==
If you don't double check your answers by substituting them back into the original equation, you may be introducing extraneous solutions into the problem which is why you should always check to confirm your answer is accurate. I hope this helps! :)
This is the concept of algebra, given that the elevator is 500ft above the ground and it is descending at a steady rate of 5ft/sec. Then height h, at time t of the elevator movement can be modeled by the equation:
h(t)=-5t+500.
The correct answer is h(t)=-5t+500
