20 x - 1 y = -200
25 x - 1 y = 0
D = -20 + 25 = 5
Dx =
| -200 -1 |
| +000 -1 | / 5
= 200/5 = 40 sign ?
Dy =
| 20 -200 |
| 25 +000 | /5
= 5000/5 = 1000
y= 20x + 200
y= 25x
D= |20 -1|. -20 - (-25)
. |25 -1| D= 5
Dx= |200 -1|. -200 - 0
. |0 -1| Dx= -200
Dy= |20 200|. 0 - 5000
. |25 0 | Dy= -5000
x= Dx/D x= -200/5 x= -40
y= Dy/D y= -5000/5 y= -1000
Is This Right?
25 x - 1 y = 0
D = -20 + 25 = 5
Dx =
| -200 -1 |
| +000 -1 | / 5
= 200/5 = 40 sign ?
Dy =
| 20 -200 |
| 25 +000 | /5
= 5000/5 = 1000
y = 20x + 200
y = 25x
Using Cramer's rule, you need to calculate the determinant (D), the determinant of x (Dx), and the determinant of y (Dy).
The determinant (D) is calculated by taking the determinant of the coefficients of x and y in the system of equations:
D = |20 -1|
|25 0 |
Calculating the determinant, we get D = (20*0) - (25*-1) = -5.
The determinant of x (Dx) is calculated by replacing the coefficients of x with the constant terms in the system of equations:
Dx = |200 -1|
| 0 -1|
Calculating the determinant, we get Dx = (200*-1) - (0*-1) = -200.
Similarly, the determinant of y (Dy) is calculated by replacing the coefficients of y with the constant terms:
Dy = |20 200|
|25 0|
Calculating the determinant, we get Dy = (20*0) - (25*200) = -5000.
Finally, the value of x can be found by dividing Dx by D:
x = Dx / D = -200 / -5 = 40.
Similarly, the value of y can be found by dividing Dy by D:
y = Dy / D = -5000 / -5 = 1000.
Therefore, the company needs to sell 40 items each week to break even.