Whats 5 - x = 12 please respond fast someone

This set of equations is conveniently solved using the matrix row-reduction features of a scientific or graphing calculator, spreadsheet, or any of a number of apps or on-line calculators.

The attachment shows the solution to be ...

(x, y, z) = (0, -6, 1)

__

<em>Additional comment</em>

Solving a system of three or more equations "by hand" often can be done by an ad hoc process. It can be done in systematic fashion using Gauss-Jordan reduction techniques, but that often gets messy. Similarly, Cramer's Rule can be used, but that math tends to involve more arithmetic operations than are really necessary.

Adding the first equation to the other two eliminates the y-variable and reduces the system to two equations in two unknowns.

(9x +y -3z) +(10x -y +2z) = (-9) +(8) . . . . adding [1] and [2]

19x -z = -1 . . . . simplified

(9x +y -3z) +(-10x -y +4z) = (-9) +(10) . . . . adding [1] and [3]

-x +z = 1 . . . . simplified

At this point, we could graph the two equations, or we can proceed algebraically.

Adding these two equations gives ...

(19x -z) +(-x +z) = (-1) +(1)

18x = 0 ⇒ x = 0

Using the second of the reduced equations, we find ...

-x +z = 1

0 +z = 1 ⇒ z = 1

And using the second of the original equations, gives us ...

10(0) -y +2(1) = 8

-y = 6 . . . . . subtract 2

y = -6 . . . . multiply by -1

Then the solution is (x, y, z) = (0, -6, 1), as above.

6 0

8 months ago

Right triangle ABC is similar to triangle XYZ. If the length of side AB is 20.8 units, the length of side BC is 36.4 units, and

trasher [3.6K]

Answer:

XY is 4 units.

Step-by-step explanation:

We are given the following in the question:

Right triangle ABC is similar to triangle XYZ.

AB = 20.8 units

BC = 36.4 units

YZ = 7 units

We have to find the length of side XY.

Since the given triangles are similar, they have the following property:

The ratio of corresponding sides of similar triangles are equal.

We can write,

$\displaystyle\frac{AB}{XY}=\frac{BC}{YZ}=\frac{AC}{XZ}$

Putting the given values, we have,

$\displaystyle\frac{AB}{XY}=\frac{BC}{YZ}\\\\\frac{20.8}{XY}=\frac{36.4}{7}\\\\XY = \frac{20.8\times 7}{36.4} =4 \text{ units}$

Thus, the length of XY is 4 units.

8 0

2 years ago

Matt Bonner has 8 dimes, 9 pennies, and 4 quarters in his pocket. If each coin is equally likely to be pulled out of his pocket

Lesechka [4]

Answer:

B. 0.602%

Step-by-step explanation:

Probability is essentially (# times specific event will occur) / (# times general event will occur). Here, we have a few specific events: draw a quarter, draw a second quarter, draw a penny, and draw another penny. The general event will just be the number of coins there are to choose from.

The probability that the first draw is a quarter will be 4 / (4 + 8 + 9) = 4/21.

Since we've drawn one now, there's only 21 - 1 = 20 total coins left. The probability of drawing a second quarter is: (4 - 1) / (21 - 1) = 3/20.

The probability of drawing a penny is: 9 / (20 - 1) = 9/19.

The probability of drawing a second penny is: (9 - 1) / (19 - 1) = 8/18.

Multiply these four probabilities together:

(4/21) * (3/20) * (9/19) * (8/18) = 864 / 143640 ≈ 0.602%

The answer is B.

8 0

2 years ago

Read 2 more answers