If p=3(2q+r), express q in terms of p and r.
1 answer:
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Answer:
(x, y) ≈ (2.848, -19.241)
Step-by-step explanation:
I find it much easier to work with the problem statement when math expressions are written using numbers and symbols. We assume you have ...
-4x +15y = -300
20x +4y = -20
Dividing the second equation by 4 and subtracting the x-term gives ...
y = -5-5x
Substituting that into the first equation, we get ...
-4x +15(-5-5x) = -300
-79x -75 = -300
x = -225/-79 = 2 67/79 ≈ 2.8481
Substituting this into the equation for y gives ...
y = -5(x +1) = -5(3 67/79) = -19 19/79 ≈ -19.2405
The approximate solution is ...
(x, y) = (2.8481, -19.2405)
Answer:
The width of the computer compartment is 9 inches
The length of the computer compartment is 33 inches
The height of the computer compartment is 27 inches
Step-by-step explanation:
The given data on the rectangular prism compartment are;
The volume of the rectangular prism, V = 8019 cubic inches
The length of the compartment, l = 24 inches + The width, w
The height of the compartment, h = 18 inches + The width, w
Therefore, we have;
l = 24 + w
h = 18 + w
V = l × h × w
∴ V = (24 + w) × (18 + w) × w = w³ + 42·w² + 432·w = 8019
w³ + 42·w² + 432·w - 8019 = 0
By graphing the above function with MS Excel, we have one of the solution is w = 9
∴ (w - 9) is a factor of w³ + 42·w² + 432·w - 8019 = 0
Dividing, we get;
w² + 51·w + 891
w³ + 42·w² + 432·w - 8019 = 0
w³ - 9·w²
51·w² - 459·w
891·w
891·w + 8019
0
Therefore,
w³ + 42·w² + 432·w - 8019 = 0
w³ + 42·w² + 432·w - 8019 = (x - 9)·(w² + 51·w + 891) = 0
The determinant of the factor, w² + 51·w + 891 = 51² - 4×1×891 = -963, therefore, the it has complex roots
Therefore, the real solution of (x - 9)·(w² + 51·w + 891) = 0 is w = 9
The width of the computer compartment, w = 9 inches
The length of the computer compartment, l = 24 inches + 9 inches = 33 inches
The height of the computer compartment, h = 18 inches + 9 inches = 27 inches.
