Since there is a linear function between the daily sales volume Y and the unit price X, let this linear function be: Y=kX+b, and the profit will be (X-8)*Y=(X-8)*(kX+b).
and
If you sell at 10 yuan/kg, you can sell 300kg every day, that is, when X= 10, Y=300, that is, 10k+b=300.
If you sell it at 13 yuan/kg, you can make a profit in 750 yuan every day. When X= 13, (X-8)*(kX+b)=750, that is, (13-8) * (13k+b) = 750.
Combining the above two equations, k=-50 and b=800.
Substitute k=-50 and b=800 into Y=kX+b to get y =-50x+800 (x >); 0)
2. solution: the price y of each line is a linear function of everyone's original price X.
Let this linear function be: y = kx+b.
When the original price X= 1800, the corresponding current price Y=2 100.
When the original price X=2300, the corresponding current price Y=2800.
Substitute (1800,2100) and (2300,2800) into the equation: y = kx+b.
Simultaneous solution: k= 1.4 b=-420.
The functional relationship between y and x is Y= 1.4X-420.
A. high school physics is very difficult. Now that my son is a sophomore, how can he learn high school physics well? Is there a better extracurricul