All categories

2 years ago

Solve 3x – y + 2z = 6 -x + y = 2 x – 2z = -5

Mathematics

1 answer:

posledela2 years ago

3 0

Answer:

Step-by-step explanation:

3x – y + 2z = 6 - - - - - - - - - 1

-x + y = 2 - - - - - - - - - - - - -2

x – 2z = -5 - - - - - - - - - - - -3

From equation 2, x = y - 2

From equation 3, x = 2z - 5

Substituting x = y - 2 and x = 2z - 5 into equation 1, it becomes

3(y - 2) – y + 2z = 6

3y - 6 - y + 2z = 6

3y - y + 2z = 6 + 6

2y + 2z = 12 - - - - - - - - - 4

3(2z - 5) – y + 2z = 6

6z - 15 - y + 2z = 6

- y + 6z + 2z = 6 + 15

- y + 8z = 21 - - - - - - - - - - 5

Multiplying equation 4 by 1 and equation 5 by 2, it becomes

2y + 2z = 12

- 2y + 16z = 42

Adding both equations

18z = 54

z = 54/18 = 3

Substituting z = 3 into equation 5, it becomes

- y + 8×3 = 21

- y + 24 = 21

- y = 21 - 24 = - 3

y = 3

Substituting y = 3 into equation 2, it becomes

-x + 3 = 2

- x = 2 - 3 = -1

x = 1

You might be interested in

What types of numbers are undefined when they are under a radical sign? If you were dealing with the number √-1, would it be def

Misha Larkins [42]

The square root of a a negative integer is imaginary.
It would still be a negative under a square root if you multiplied it by 2, therefor it will still be imaginary, or I’m assuming as your book calls it, undefined.
2•(sqrt-1) = 2sqrt-1

If you add a number to -1 itself, specifically 1 or greater it will become a positive number or 0 assuming you just add 1. In that case it would be defined.
-1 + 1 = 0
-1 + 2 = 1

If you add a number to the entire thing “sqrt-1” it will not be defined.
(sqrt-1) + 1 = 1+ (sqrt-1)

If you subtract a number it will still have a negative under a square root, meaning it would be undefined.
(sqrt-1) + 1 = 1 + (sqrt-1)

however if you subtract a negative number from -1 itself, you end up getting a positive number or zero. (Subtracting a negative number is adding because the negative signs cancel out).
-1 - -1 = 0
-1 - -2 = 1

If you squared it you would get -1, which is defined
sqrt-1 • sqrt-1 = -1

and if you cubed it, you would get a negative under a square root again, therefor it would be undefined.
sqrt-1 • sqrt-1 • sqrt-1 = -1 • sqrt-1 = -1(sqrt-1)

Sorry if this answer is confusing, I don’t have a scientific keyboard, I’ll get one soon.

8 0

2 years ago

What perfect square that is between 1 and 100 has 27 as one of its factors?

astra-53 [7]

Answer:

Step-by-step explanation:

Its a perfect square and 27*3=81

6 0

2 years ago

Y=4x-6 and passes through point 8,12

umka2103 [35]

Answer:

Slope of required line if both lines are parallel: y=4x-20

Slope of required line if both lines are perpendicular: y=-1/4x+14

Step-by-step explanation:

We need to find equation of line while we are given another line having equation y=4x-6 and passes through point (8,12)

<u><em>Note: Since it is not given if the required line is parallel or perpendicular to the given line. I will solve for both cases.</em></u>

If Both lines are parallel the equation of new line will be:

We need to find slope and y-intercept to write equation of new line.

When lines are parallel there slopes are same

So, slope of given line y=4x-6 is 4 (Compare with general equation y=mx+b, m is slope so m=4)

Slope of new line is: m=4

Now finding y-intercept

Using slope m=4 and point (8,12) we can find y-intercept

$y=mx+b\\12=4(8)+b\\12=32+b\\b=12-32\\b=-20$

y-intercept of new line is: b=-20

Equation of required line having slope m=4 and y-intercept b=-20 is

$y=mx+b\\y=4x-20$

If Both lines are perpendicular the equation of new line will be:

We need to find slope and y-intercept to write equation of new line.

When lines are perpendicular there slopes are opposite of each other

So, slope of given line y=4x-6 is 4 (Compare with general equation y=mx+b, m is slope so m=4)

Slope of new line is: m=-1/4

Now finding y-intercept

Using slope m=-1/4 and point (8,12) we can find y-intercept

$y=mx+b\\12=-\frac{1}{4} (8)+b\\12=-2+b\\b=12+2\\b=14$

y-intercept of new line is: b=14

Equation of required line having slope m=-1/4 and y-intercept b=14 is

$y=mx+b\\y=-\frac{1}{4} x+14$

8 0

2 years ago

A farmer grows corn, tomatoes, and sunflowers on a 320-acre farm. This year, the farmer wants to plant twice as many acres of to

svet-max [94.6K]

Set it up with variables; tomatoes=t, sunflowers=s, corn=c

320=t+s+c

This year;
t=2s
c=t+40

so, replace 2s for t; c=2s+40

now we can put those factors in for 320=t+c+s

320= 2s+2s+40+s
(SIMPLIFY)---> 320=5s+40----> 5s+280----> s=56

now incorporate the s value into the other equations.

c=2s+40----> c=56(2)=40 ----> c=152
t=2s -----> t=2(56) ----> t=112

TOMATOES= 112 acres
CORN= 152 acres
SUNFLOWERS= 56 acres

To check your work: 320=t+s+c ----> 320=112+156+56

5 0

2 years ago

Read 2 more answers

Explain how you know two triangles are the same

Zina [86]

Through SSS, SAS, ASA, HL, AAS
S=side
A=angle
And HL= hypotenuse leg
If conditions are congruent for each pair of three

4 0

2 years ago