Solve 3x3-6. Graph the solution. A) B) C) D)

g Given the system of equations: 15 c1 – 5 c2 – c3 = 2400 - 5 c1 + 18 c2 – 6 c3 = 3500 - 4 c1 - c2 + 12 c3 = 4000 (a) Calculate

denpristay [2]

Answer

(a)

$A^{-1} = \frac{1}{3493} \begin{pmatrix} 210 && -59 && -12 \\ 84 && 176 && 95 \\ 77 && -5 && 295 \end{pmatrix}$

(b)

$A^{-1} b = \begin{pmatrix} \frac{500}{7} \\\\ \frac{2400}{7} \\\\ \frac{2700}{7} \end{pmatrix}$

Step-by-step explanation:

Remember that when you want to solve a problem like this, you express the equation as following

$Ax = b$

So, if you know the inverse of $A$ then

$x = A^{-1} b$

For this case

$A = \begin{pmatrix} 15 && 5 && -1 \\ -5 && 18 && -6 \\ -4 && -1 && 12 \end{pmatrix}$

Now for this case the inverse of A would be

$A^{-1} = \frac{1}{3493} \begin{pmatrix} 210 && -59 && -12 \\ 84 && 176 && 95 \\ 77 && -5 && 295 \end{pmatrix}$

Then when you multiply with the vector solution

$A^{-1} b = \frac{1}{3493} \begin{pmatrix} 210 && -59 && -12 \\ 84 && 176 && 95 \\ 77 && -5 && 295 \end{pmatrix} * \begin{pmatrix} 2400 \\ 3500 \\ 4000 \end{pmatrix} = \frac{1}{3493} \begin{pmatrix} 249500 \\ 1197600 \\ 1347300 \end{pmatrix}\\\\\\= \begin{pmatrix} \frac{500}{7} \\\\ \frac{2400}{7} \\\\ \frac{2700}{7} \end{pmatrix}$

So from that information you can conclude that the solution to the system of equations is x = 500/7 y = 2400/7 and z = 2700/7

7 0

2 years ago

Which of the following is a solution of y> |x| - 5? (4,-1) (-1,-4) (-4, 1)

Marrrta [24]

Answer:

(-4,1)

Step-by-step explanation:

Let us check the choices.

y > |x| - 5

- 1 > |4| - 5 = -1 NO (4,-1);

-4 > |-1| - 5 = -4 NO not(-1,-4)

1 > |-4| - 5 = -1 TRUE, yes (-4,1)

4 0

3 years ago

5 common multibles of 7 and 20

uranmaximum [27]

7 = 7
20 = 2 x 2 x 5

Least common multiple is 2 x 2 x 5 x 7 = 140
Other multiples are multiples of 140 = 280, 420, 560, 700

3 0

2 years ago

Pretty sure i know the answer. will reward brainliest just because.

Oksi-84 [34.3K]

Answer:

since 20% is 100

then 80% is 400

Therefore 500 in total to begin with.

6 0

3 years ago

Read 2 more answers

Explain what Shawna's error is plz.

kondor19780726 [428]

Our Order of Operations looks like this:
Parenthesis
Exponent
Multiplication/Division
Addition/Subtraction

Multiplication and division are on the same "level".
When we see them in the problem, we execute the operations from LEFT TO RIGHT. So Shawna should have applied the division before multiplying the 2 and 3. (Because the division is the leftmost operation in the problem).

6 0

3 years ago