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4 years ago

Solve the equation. 3(x – 9) = 30

Mathematics

2 answers:

Dima020 [189]4 years ago

4 0

3(x-9)=30
3x-27=30
+27 +27
3x=57
x=19

KiRa [710]4 years ago

3 0

First you expand the brackets:
3x - 27 = 30
And then you can solve:
3x - 27 = 30
+ 27
3x = 57
÷ 3
x = 19
Hope this helps!

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In 1983, a year-long newspaper subscription cost $12.75. Today, a year-long newspaper subscription costs $28.50. If the CPI is 1

disa [49]

The CPI or the Customer Price Index is calculated through the equation,
CPI = (price at a certain year/ price at the base year) x 100
If our base year is 1983, the price of a year-long newspaper subscription will cost,
193 = (price at a certain year / 12.75) x 100
price at a certain year = $24.6075
Thus, the current price which is $28.50 is slightly higher than the expected price based on the given CPI.

8 0

4 years ago

Solve: <br> 6f-7z where f=3 and z=2.

vivado [14]

Answer:

Step-by-step explanation:

We have 6f - 7z, where f = 3 and z = 2. Essentially, we just plug in these values:

6f - 7z

6 * 3 - 7 * 2

18 - 14

The answer is thus 4.

<em>~ an aesthetics lover</em>

6 0

3 years ago

Read 2 more answers

Five tenths percent of what number is twelve

BigorU [14]

Answer:

Step-by-step explanation:

5/10 is 1/2 or .5 As a percentage, this is .5%, and as a decimal it's .005. Using this in an equation, .005x = 12. Divide 12 by .005 to get 2400

6 0

3 years ago

I need to find the missing numbers

const2013 [10]

Answer:

b11 = -14

b12 = 9

b13 = 8

Step-by-step explanation:

* Lets revise some notes to solve the problem

- Any matrix has a dimension m × n, where m is the number of rows

and n the number of columns

- We can add matrices with same dimensions

* Now lets solve the problem

∵ $B+\left[\begin{array}{ccc}15&-7&4\\0&1&2\end{array}\right]=\left[\begin{array}{ccc}1&2&12\\4&0&2\end{array}\right]$

- Let $B=\left[\begin{array}{ccc}b11&b12&b13\\b21&b22&b23\end{array}\right]$

∴ $\left[\begin{array}{ccc}b11&b12&b13\\b21&b22&b23\end{array}\right]+\left[\begin{array}{ccc}15&-7&4\\0&1&2\end{array}\right]=\left[\begin{array}{ccc}1&2&12\\4&0&2\end{array}\right]$

- Lets add and find the missing

* Lets start with the first rows

∵ b11 + 15 = 1 ⇒ subtract 15 from both sides

∴ b11 = -14

∵ b12 + -7 = 2 ⇒ add 7 to both sides

∴ b12 = 9

∵ b13 + 4 = 12 ⇒ subtract 4 from both sides

∴ b13 = 8

* Now lets start with the second rows

∵ b21 + 0 = 4

∴ b21 = 4 ⇒ given

∵ b22 + 1 = 0 ⇒ subtract 1 from both sides

∴ b22 = -1 ⇒ given

∵ b23 + 2 = 2 ⇒ subtract 2 from both sides

∴ b23 = 0 ⇒ given

5 0

3 years ago

Fernando is playing hide-and-seek with Darnel and Joy. Darnel is hiding 5 meters south of Fernando, and Joy is hiding due east o

pashok25 [27]

Answer:

<h2>6.2 metres apart</h2>

Step-by-step explanation:

Find attached a diagram for proper elucidation of the question. The resulting shape is a right angled triangle with hypotenuse FJ, and the other two sides DF and DJ respectively.

Using Pythagoras theorem to get the side DJ which is the distance between Daniel and Joy. <em>According to the theorem, the square of the hypotenuse of a right angled triangle is equal to the sum of the other two sides. </em>

FJ² = DF² + DJ²

From the diagram, FJ = 8 and DF = 5. Substituting this values into the theorem above to get DJ;

8² = 5²+DJ²

DJ² = 8²-5²

DJ² = 64 -25

DJ² = 39

DJ = √39

DJ = 6.2 (to the nearest tenth)

This shows that Darnel is 6.2 metres away from Joy

8 0

3 years ago