Answer:
<h3>B. -84</h3>
Step-by-step explanation:
Taking the determinant of the matrices we will have;
= 4x(5y) - 2x(3y)
= 20xy - 6xy
= 14xy
Given x = -2 and y = 3
Determinant = 14(-2)(3)
Determinant = -28*3
Determinant = -84
9514 1404 393
Answer:
Step-by-step explanation:
The equation for the total number of cases is ...
x + y = 20
The equation for the total cost of the cases is ...
20x +30y = 450
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<em>Additional comment</em>
The solution to these equations is (x, y) = (15, 5).