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4 years ago

Questions 23-26 I need help with

Mathematics

2 answers:

LUCKY_DIMON [66]4 years ago

8 0

Answer:

23. b

24. c

25. b

26. c

Step-by-step explanation:

23. In problem 21, you found the coefficient matrix to be ...

$\left[\begin{array}{ccc}2&-3&1\\1&2&-4\\-3&-2&3\end{array}\right]$

Its determinant is ...

(2)(2)(3) +(-3)(-4)(-3) +(1)(1)(-2) -(-3)(2)(1) -(-2)(-4)(2) -(3)(1)(-3)

= 12 -36 -2 +6 -16 +9 = -27 . . . . choice b

24. Looking at the equation involving x11 terms, we have ...

-3x +7 = 10

-3x = 3 . . . . . subtract 7

x = -1 . . . . . . divide by -3 . . . . matches choices A and C

We note that choices A and C differ in their values for x22, so we consider the equation for that:

-3x -3 = -18

x + 1 = 6 . . . . . . . divide by -3

x = 5 . . . . . . . . matches choice C

25. Dx will be the determinant of the matrix with the constants in the first column. Choice B is the only one that matches.

26. The value of Dx is -78 +24 = -54. The determinant of the coefficient matrix is (5)(6) -(-3)(-4) = 30 -12 = 18. So the value of x is -54/18 = -3, which matches choice C.

suter [353]4 years ago

7 0

See the attached picture:

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3 years ago

This table gives a few (x, y) pairs of a line in the coordinate plane.

katrin2010 [14]

Answer:

The x-intercept is : (22, 0)

Step-by-step explanation:

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5 0

3 years ago

Need help

kow [346]

$1)\\\\\dfrac{-45}{-5}=45:5=9$

$2)\\(-2)(4)=-8\\(2)(-4)+-8\\-16:2=-8\\-16:(-2)=8\neq-8\\\\\text{All of the following expressions have the same value except}\ -16:-2.$

$3)\\-3^2=-3\cdot3=-9$

$(-2)^4=(-2)(-2)(-2)(-2)=16\\-2^4=-(2)(2)(2)(2)=-16\neq16\\(-2)(-2)(-2)(-2)=16\\2^4=(2)(2)(2)(2)=16\\\\\text{All of the following are equivalent except}\ -2^4.$

3 0

4 years ago

Did i get this right?

Margarita [4]

No it is C-2,-3 D-2,5 hope this helps

7 0

3 years ago

Questions 23-26 I need help with​

Questions 23-26 I need help with