Answer:
130
Step-by-step explanation:
You want the determinant of the matrix ...
One way to figure it is as the difference between the sum of products of the down-diagonals and the sum of products of the up-diagonals:
D = (4)(1)(3) +(3)(5)(-1) +(2)(-3)(-4) -(-1)(1)(2) -(-4)(5)(4) -(3)(-3)(3)
= 12 -15 +24 +2 +80 +27
D = 130
The determinant of the coefficient matrix is 130.
_____
Many scientific and graphing calculators and web sites can perform this calculation for you.
Answer:
$500
Step-by-step explanation:
We can find the original price of the camera through a proportion. A proportion is an equation where two ratios or fractions are equal. The ratios or fractions compare like quantities.
<u>Second Discount</u>
20% off means we paid 80%. We know we paid $328 of some price.
I can now cross-multiply by multiplying numerator and denominator from each ratio.
I now solve for y by dividing by 80.
The price after the first discount was $410.
<u>First Discount</u>
We will repeat the steps above with $410. 18% off means we paid 82%.
I can now cross-multiply by multiplying numerator and denominator from each ratio.
I now solve for y by dividing by 82.
The original price was $500.