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3 years ago

Solve the equation 4x^2 - 12x = 7 algebraically for x.

1 answer:

azamat3 years ago

3 0

$4x^2-12x=7\\4x^2-12x-7=0\\x=\frac{-b+-\sqrt{b^2-4ac}}{2a}\\x=\frac{-(-12)+-\sqrt{(-12)^2-4(4)(-7)}}{2(4)}\\x=\frac{12+-\sqrt{144+112}}{8}\\x=\frac{12+-\sqrt{256}}{8}\\x=\frac{12+-16}{8}\\x=\frac{-4,28}{8}\\x=\frac{-1}{2},\frac{7}{2}$

x = -0.5, 3.5

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The students in Mrs. Willow's reading class are all reading the same novel independently. Four students create a graph of their

Dovator [93]

Answer:

see the explanation

Step-by-step explanation:

Let

x ----> the time in minutes

y ---> the number of words reading

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form $k=\frac{y}{x}$ or $y=kx$

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin

In this problem, the relationship between x, and y, represent a proportional variation

The linear equation is equal to

$y=kx$

where

k is the constant of proportionality or the reading rate in words per minute

therefore

The student who reads fastest is the one whose equation has the highest proportionality constant or whose graph has the steepest line slope

Example

If you have

$y_1=23x\\y_2=35x\\y_3=50x\\y_4=20x$

The student who reads fastest is the number 3

Because the value of k=50 words/minute is greater

8 0

3 years ago

Read 2 more answers

The price of a new car is $20,000. If it has a depreciation rate of 18% per year, what is its value in 3 yr?

KonstantinChe [14]

Answer: After 3 years the value of the new car would be $11,027.36

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3 years ago

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How many of the positive divisors of 2160 are multiples of 3?

TEA [102]

30 of the divisors are multiples of 3

The factors of 2160 are 1, 2160, 2, 1080, 3, 720, 4, 540, 5, 432, 6, 360, 8, 270, 9, 240, 10, 216, 12, 180, 15, 154, 16, 135, 18, 120, 20, 108, 24, 90, 27, 80, 30, 72, 36, 60, 40, 54, 45, 48
These are all divisors of 2160 but only 30 are multiples of 3.
The ones that are NOT are 1, 2, 4, 5, 8, 10, 16, 20, 40 and 80

You can also do this using prime factors 2x2x2x2x3x3x3x5 = 2160 but it is harder to explain.

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3 years ago

If f(x) = 5-2x find f(9)+ 3

ioda

f (9) = 5 - 2 (9)

f (9) = 5 - 18

f (9) = - 13

f (9) + 3 = - 13 + 3

f (9) + 3 = - 10

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3 years ago

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Jordan wrote the following description: Three fewer than one fourth of x is 12. Write an

muminat

Answer:

x/4 - 3 = 12

Step-by-step explanation:

"one fourth of x" is x/4.

Then "three fewer than one fourth of x is 12" becomes, symbolically,

x/4 - 3 = 12

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3 years ago