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3 years ago

Solve the system by substitution. (Please Explain how you did it Ill give brainliest)

2 answers:

5 0

Because the last equation already has the y eliminated so just need to get the other two to eliminate the y too

multiply 4 to the first equation to eliminate y, and you get
-4x-4y-4z=-32
-4x+4y+5z=7
now get rid of y so all you have left is
-8x+z=-25 (let call this equation #4)

now take equation #3 and #4 together to solve for one of the variables, i’ll solve for z first so i’ll get rid of x by multiply the equation #4 all by 4, you get

8x+8z=16
-8x+z=-25
solve it and get 9z= -9; z=-1

now you have z so take it and ply it into equation #3
2x+2(-1)=4
2x=6; x=3

take both of them, plug it in equation #1
-3-y-(-1)=-8
-y=-6 ; y=6

done so the answer is (x,y,z) = (3,6,-1)

konstantin123 [22]3 years ago

5 0

Answer:

(x, y, z) = (3, 6, -1

Step-by-step explanation:

You can make a simple expression to substitute for x using the last equation.

2x = 4 -2z

x = 2 - z . . . . . . divide by 2

Now, substitute that into the first equation:

-(2 -z) -y -z = -8 . . . .substitute for x

-2 +z -y -z = -8 . . . . eliminate parentheses

-2 -y = -8 . . . . . . . . . simplify

6 = y . . . . . . . . . . . . add 8+y

We can substitute for both x and y in the second equation:

-4(2 -z) +4(6) +5z = 7

-8 +4z +24 +5z = 7 . . . . . eliminate parentheses

9z = -9 . . . . . . . . . . . . . . .simplify, subtract 16

z = -1 . . . . . . . . . . . . . . . . . divide by 9

And from our expression for x, we get ...

x = 2 - z = 2 -(-1) . . . . . substitute for z

x = 3

The solution is (x, y, z) = (3, 6, -1).

You might be interested in

The width of a rectangular rug is 6 feet if the perimeter is 24 feet what is the area of the rug?

babymother [125]

Answer:

36 feet squared

Step-by-step explanation:

Finding the perimeter of an object is adding all of the sides together. If the width of the rug is 6 feet then we know that there are two sides that length. Add those together.

6 feet + 6 feet = 12 feet

You would subtract the number you get from the perimeter.

24 feet - 12 feet = 12 feet

And then divide the number by the number of sides left, 2, to get each of their lengths.

12 feet / 2 feet = 6 feet

To find the area of a rectangle you multiply length times width, which in this case both are 6 feets.

6 feet x 6 feet = 36 feet squared

6 0

3 years ago

Which number will have the same result when rounded to the nearest ten or hundred A-97 B-118and5 C-179 D-5091

slamgirl [31]

Lets round it to the nearest ten
A 97 ====> 100
B 118 ===> 120
C 179 ===> 180
D 5091 ==> 5090
No result yet, lets round to the nearest hindred.
A 97 ====> 100
B 118 ===> 100
C 179 ===> 180
D 5091 ==> 5100
As we can see only A give the same result when we round it to the nearest hundred and nearest ten.

5 0

4 years ago

Will yall help me pleaseee! I need this turned in today donttake my points :'( this is Pythagorean Math !!!!

LenaWriter [7]

Answer:

1. 7.6 = c

2. 45 = c

Step-by-step explanation:

1. 3^2 + 7^2 = c^2

9 + 49 = c^2

58 = c^2

square root both sides = 7.6 = c

2. 27^2 + 36^2 = c^2

729 + 1296 = c^2

2025 = c^2

square root both sides

c = 45

5 0

3 years ago

Which ordered pair would form a proportional relationship with the point graphed below? (60,-20)

valentina_108 [34]

Given:

The graphed point is (60,-20).

To find:

The ordered pair that would form a proportional relationship with the given point.

Solution:

If y is proportional to x, then

$y\propto x$

$y=kx$

$\dfrac{y}{x}=k$

Where, k is the constant of proportionality.

For the given point,

$k=\dfrac{-20}{60}$

$k=\dfrac{-1}{3}$

For option (A),

$k=\dfrac{30}{-10}$

$k=-3\neq \dfrac{-1}{3}$

For option (B),

$k=\dfrac{-15}{30}$

$k=-\dfrac{1}{2}\neq \dfrac{-1}{3}$

For option (C),

$k=\dfrac{10}{-30}$

$k=\dfrac{-1}{3}$ .

The point (-30,10) gives the same value of the constant of proportionality. So, the point (-30,10) forms a proportional relationship with the given point.

Therefore, the correct option is C.

7 0

3 years ago

What is the sum 13,094 259,728?

fgiga [73]

Thank you for posting your question here at brainly. I will assume that the equation is that <span>13,094 + 259,728. Below is the solution:

</span>13,094 + 259,728 = 272,822

Sum is t<span>he total amount resulting from the addition of two or more numbers, amounts, or items.</span>

6 0

4 years ago