Final answer:
The rate of change of the demand with respect to time is 22.6 items/month.
Step-by-step explanation:
To find the rate of change of the demand with respect to time, we need to first differentiate the equation of the demand curve with respect to time. Differentiating 2x² - 7xp + 60p² = 25,600:
4x(dx/dt) - 7p(dx/dt) - 7x(dp/dt) + 120p(dp/dt) = 0
Next, we substitute the given values:
4x(dx/dt) - 7(20)(2) - 7x(dp/dt) + 120(20)(2) = 0
At this point, we can solve for dx/dt:
4x(dx/dt) - 280 - 14x(dp/dt) + 4800 = 0
(4x - 14x)(dx/dt) = (280 - 4800)
(-10x)(dx/dt) = -4520
dx/dt = 4520 / (-10x)
Now, we can use the given information that the price is increasing at a rate of 2 dollars per month when the price is 20 dollars. Substitute these values into the equation:
dx/dt = 4520 / (-10(20))
dx/dt = 4520 / (-200) = 22.6 items/month