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3 years ago

What is the value of x if the average of 10, 11, 12 and x is 9?

Mathematics

1 answer:

frosja888 [35]3 years ago

6 0

Answer: The value of x is 3.

Step-by-step explanation:

Since we have given that

10,11, 12 and x

Average of above numbers = 9

As we know that

Average is given by

$\dfrac{\text{Sum of observation}}{\text{Number of observation}}\\\\\\\dfrac{10+11+12+x}{4}=9\\\\10+11+12+x=9\times 4\\\\33+x=36\\\\x=36-33\\\\x=3$

Hence, the value of x is 3.

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Write an equation (a) in slope-intercept form and (b) in standard form for the line passing through (-3,5) and parallel to x + 4

Dmitry [639]

Answer:

$\boxed{\sf Standard-form :x + 4y -17=0 }\\$

$\boxed{\sf Slope-intercept\ form :y =\dfrac{-1}{4}x +\dfrac{17}{4}}$

Step-by-step explanation:

Here a equation of the line is given to us and we need to find out the equation of line which passes through the given point and parallel to the given line , the given equation is ,

$\longrightarrow x + 4y = 7\\$

Firstly convert it into slope intercept form of the line which is y = mx + x , as ;

$\longrightarrow 4y = -x + 7 \\$

$\longrightarrow y =\dfrac{-x}{4}+\dfrac{7}{4}\\$

On comparing it to y = mx + c , we have ,

$\longrightarrow m =\dfrac{-1}{4}\\$

$\longrightarrow c =\dfrac{7}{4}\\$

Now as we know that the slope of two parallel lines is same . Therefore the slope of the parallel line will be ,

$\longrightarrow m_{||)}=\dfrac{-1}{4}\\$

Now we may use point slope form of the line as ,

$\longrightarrow y - y_1 = m(x-x_1) \\$

On substituting the respective values ,

$\longrightarrow y - 5 =\dfrac{-1}{4}\{ x -(-3)\}\\$

$\longrightarrow y -5=\dfrac{-1}{4}(x+3)\\$

$\longrightarrow 4(y -5 ) =-1(x +3) \\$

$\longrightarrow 4y -20 = - x -3 \\$

$\longrightarrow x + 4y -20+3=0\\$

$\longrightarrow \underset{Standard \ Form }{\underbrace{\underline{\underline{ x + 4y -17=0}}}} \\$

Again the equation can be rewritten as ,

$\longrightarrow y - 5 = \dfrac{-1}{4}(x +3) \\$

$\longrightarrow y = \dfrac{-1}{4}x -\dfrac{3}{4}+5 \\$

$\longrightarrow y = \dfrac{-1}{4}x -\dfrac{20-3}{4} \\$

$\longrightarrow \underset{Slope-Intercept\ form }{\underbrace{\underline{\underline{ y =\dfrac{-1}{4}x +\dfrac{17}{4}}}}}\\$

6 0

2 years ago

Liza finished studying at half past 3. What time did Liza finish studying?

Lady_Fox [76]

3:30

Half past means 30 min after

Hope this helped!

3 0

3 years ago

Read 2 more answers

I need help with all of these. I’m bad at them. Tell me how you solved for this please

Greeley [361]

1) online has the lower unit price

27.25 / 5 = 5.45

32.16 / 6 = 5.3583333.... rounded it would be

5.35

2) The cost of 7 pounds would be 103.18

73.70 / 5 = 14.74 (cost of one pound)

14.74 x 7 = 103.18

3) The scarf in October costed more

13.35 / 3 = 4.45 (one scarf)

22.65 / 5 = 4.53

hope this helps

3 0

3 years ago

Can someone please show me only how to do the number 6 through 9 step by step number bonds it’s so confuse to me please

KengaRu [80]

Answer:

I think it's just 2 numbers you add together to get that number. for example number 6 you could add 10 and 5 in the circles to get 15 then you add 15 and 4 to get 19

3 0

3 years ago

An object is propelled upward from the top of a 300 foot building. The path that the object takes as it falls to the ground can

serg [7]

Answer:

As per the statement:

The path that the object takes as it falls to the ground can be modeled by:

h =-16t^2 + 80t + 300

where

h is the height of the objects and

t is the time (in seconds)

At t = 0 , h = 300 ft