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3 years ago

Linar system in variables -x-3y-2z=8, -x+y+6z=, x-9y-2z=4

Mathematics

1 answer:

docker41 [41]3 years ago

8 0

Answer:

-x+y+6z=? You did not spcify so I just made it 0

x = -22/5, y = -4/5, z = -3/5

Step-by-step explanation:

Solve the following system:

{-x - 3 y - 2 z = 8 | (equation 1)

-x + y + 6 z = 0 | (equation 2)

x - 9 y - 2 z = 4 | (equation 3)

Subtract equation 1 from equation 2:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x+4 y + 8 z = -8 | (equation 2)

x - 9 y - 2 z = 4 | (equation 3)

Divide equation 2 by 4:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x+y + 2 z = -2 | (equation 2)

x - 9 y - 2 z = 4 | (equation 3)

Add equation 1 to equation 3:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x+y + 2 z = -2 | (equation 2)

0 x - 12 y - 4 z = 12 | (equation 3)

Divide equation 3 by 4:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x+y + 2 z = -2 | (equation 2)

0 x - 3 y - z = 3 | (equation 3)

Swap equation 2 with equation 3:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x - 3 y - z = 3 | (equation 2)

0 x+y + 2 z = -2 | (equation 3)

Add 1/3 × (equation 2) to equation 3:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x - 3 y - z = 3 | (equation 2)

0 x+0 y+(5 z)/3 = -1 | (equation 3)

Multiply equation 3 by 3:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x - 3 y - z = 3 | (equation 2)

0 x+0 y+5 z = -3 | (equation 3)

Divide equation 3 by 5:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x - 3 y - z = 3 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Add equation 3 to equation 2:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x - 3 y+0 z = 12/5 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Divide equation 2 by -3:

{-x - 3 y - 2 z = 8 | (equation 1)

0 x+y+0 z = -4/5 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Add 3 × (equation 2) to equation 1:

{-x + 0 y - 2 z = 28/5 | (equation 1)

0 x+y+0 z = -4/5 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Add 2 × (equation 3) to equation 1:

{-x+0 y+0 z = 22/5 | (equation 1)

0 x+y+0 z = -4/5 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Multiply equation 1 by -1:

{x+0 y+0 z = -22/5 | (equation 1)

0 x+y+0 z = -4/5 | (equation 2)

0 x+0 y+z = -3/5 | (equation 3)

Collect results:

Answer: {x = -22/5, y = -4/5, z = -3/5

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3 years ago

How do work this out

BabaBlast [244]

We can factor this by using grouping. Take the leading coefficient and multiply it by the constant. In this case we get 5*-7 = -35.

Now we need 2 numbers that add to 2 and multiply to be -35. The numbers are -5 and 7.

So split the 2r into these two terms and group.

(5r^2 - 5r) + (7r - 7)

Factor both groups.

5r(r-1) + 7(r-1)

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6 0

3 years ago

I need help with this math question on my study guide!

dalvyx [7]

Sadly is right. You must have practiced this stuff in middle school
until it was coming out of your ears. Fortunately, you have a chance
to relearn it now. You should do that ... it'll be important in any math
course you ever take.

'm' is the slope of the line on the graph.

The slope is

      (the change in 'y' between any two points on the line)
divided by
   (the change in 'x' between the same two points).

You can choose any two points on the line, and the slope is always the same.

To make it easy, look at the two points on this graph where the line crosses
the x-axis and the y-axis.

Going between these two points ...
-- the line goes up, from y=0 to y=4. The change in 'y' is 4 .
-- the line goes to the right, from x=-2 to x=0. The change in 'x' is 2 .

   'm' = the slope = (4)/(2) = 2 .

The "y-intercept" is the place where the line crosses the y-axis.
On this graph, that's the point where y=4 .

The equation of EVERY straight line on ANY graph is:

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So the equation of THIS line on THIS graph is

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5 0

3 years ago

bezimeni [28]

Answer:

260 stickers

Step-by-step explanation:

Let Gareth's stickers be x.

Hence Cheryl sticker is 160+x;

If Cheryl gave 185 stickers

to Gareth, it means:

Cheryl has at the moment;

160 + x - 185 = x - 25

At this time when Gareth receives 185 he now has:

x+ 185

Also when he receives x +185, he has 3 times Cherry's meaning:

x+185 =3(x-25)

x + 185 = 3x -75

185 + 75 = 3x-2x

260= x

x = 260.

Hence Gareth has 260 stickers

5 0

3 years ago

The jaguars scored 37 points their first game. They scored 58 points their second game. What is their percent change?

aliina [53]

Answer:

Change in percent = 56.75 (Approx.)

Step-by-step explanation:

Given:

Score in first game = 37 points

Score in second game = 58 points

Find:

Change in percent

Computation:

Change in percent = [(Score in second game - Score in first game)/Score in first game]100

Change in percent = [(58-37)/37]100

Change in percent = [(21)/37]100

Change in percent = 56.75 (Approx.)

7 0

2 years ago