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3 years ago

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

Mathematics

1 answer:

posledela3 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

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Last question please

MatroZZZ [7]

Let's try an make a formula to make things easy.

_________________________________________________

Look at Andrew's pattern, it goes up 6 every time. Lets look at the 6 times table

6 times table: 6, 12, 18, 24, ...

____________________________________

First think, how would you work out the 7th term in the 6th times table?

You would do 6 times 7.

So the formula for the 6th times table is:

6n (where n is the term you want to find out)

_______________________________________

So to get the 9th term in the 6 times table, you would replace the n with 9, like so:

9th term in 6 times table = 6 x 9 = 54

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Now lets compare the 6 times table to Andrew's pattern:

6 times table: 6, 12, 18, 24,

Andrew's pattern: 3, 9, 15, 21,

_____________________________________

If you look, you can see that Andrew's pattern is the 6 times table minus 3!

So what would be the formula for Andrew pattern?

---> it would be: 6n - 3 (since it's the 6 times table but minus 3)

_____________________________________

We can use this formula to easily work out the 20th term in Andrew's pattern!:

20th term = 6 x 20 - 3 = 120 - 3 = 117 (remember, replace the n with 20)

______________________________________

Now let's make a formula for Ben's pattern!

Ben's pattern goes up in 5s, so lets compare it to the 5 times table:

5 times table: 5, 10, 15, 20

Ben's pattern: 3, 8, 13, 18,

The formula for the 5 times table is 5n, and Ben's pattern is the 5 times table but minus 2.

So the formula for Ben's pattern is: 5n - 2

__________________________________

Now swap out the n for 20 (to get the 20th term):

20th term = 5 x 20 - 2 = 100 - 2 = 98

_________________________________________

So Andrew's 20th term is 117, and Ben's 20th term is 98.

All we do now is subtract them to find the difference:

117 - 98 = 19

- - - - - - - - - - - - - - - - - - - - - - - - -

Answer:

Ben's 20th term is smaller by 19!

- - - - - - - - - - - - - - - - - - - - - - - - - -

5 0

3 years ago

4-3x2 + x2 + 5x – 7)

kompoz [17]

Answer:

7x - 9

Step-by-step explanation:

1: Multiply the numbers

4 - 3 x 2 + 2x + 5x - 7

4 - 6 + 2x + 5x - 7

2: Add the numbers

4 - 6 + 2x + 5x - 7

-9 + 2x + 5x

3: Combine like terms

-9 + 2x + 5x

-9 + 7x

4: Rearange terms

-9 + 7x

7x - 9

Solution

7x - 9

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3 years ago

Tengo que simplificar esta fracción 84/105: ¡Ayudarme porfavor!

koban [17]

Answer:

Step-by-step explanation:

84/105 = 4/5

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2 years ago

X=8 in standard form Please help ASAP

Bas_tet [7]

Answer:

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3 years ago

A high school administrator is interested in determining the relationship between high school students' final grades in geometry

Radda [10]

Answer: c. On average, a 1 percentage point difference in chemistry score is associated with a 0.919 percentage point difference in geometry score

Step-by-step explanation:

Given that:

Slope value = 0.91857341

The dependent and independent variables are ;

Dependent Variable: Geometry

Independent Variable: Chemistry

Slope is the rate of change in the dependent variable per unit change in the independent variable.

Hence, from the information given, we can conclude that for every 1% change in chemistry score (independent variable), there is a corresponding approximately 0.919% change in geometry score (dependent variable).

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3 years ago