All categories

2 years ago

Answer quickly please! - 4(2.5x - 1.25) - 3x

Mathematics

2 answers:

Margarita [4]2 years ago

6 0

Answer:

-13x+5

Step-by-step explanation:

It would be greatly appreciated if you gave me brainlest

ale4655 [162]2 years ago

3 0

Answer:

-13x+5

Step-by-step explanation:

Distributive Property

-4 (2.5x) + (-4)(-1.25) - 3x

Multiply 2.5 by -4

- 10x - 4 * 1.25 - 3x

Multiply -4 by 1.25

- 10x + 5 -3x

Subtract 3x from -10x

-13x + 5

Hope this helped!

You might be interested in

-12x + 18y = 21<br>(6x -9 = -9

Leokris [45]

Answer:

x = 0 , y = 7/6

Step-by-step explanation:

Solve the following system:

{18 y - 12 x = 21

6 x - 9 = -9

In the second equation, look to solve for x:

{18 y - 12 x = 21

6 x - 9 = -9

Add 9 to both sides:

{18 y - 12 x = 21

6 x = 0

Divide both sides by 6:

{18 y - 12 x = 21

x = 0

Substitute x = 0 into the first equation:

{18 y = 21

x = 0

In the first equation, look to solve for y:

{18 y = 21

x = 0

Divide both sides by 18:

{y = 7/6

x = 0

Collect results in alphabetical order:

Answer: {x = 0 , y = 7/6

4 0

3 years ago

1) Determine the discriminant of the 2nd degree equation below:

Aleksandr-060686 [28]

$\LARGE{ \boxed{ \mathbb{ \color{purple}{SOLUTION:}}}}$

We have, Discriminant formula for finding roots:

$\large{ \boxed{ \rm{x = \frac{ - b \pm \: \sqrt{ {b}^{2} - 4ac} }{2a} }}}$

Here,

x is the root of the equation.
a is the coefficient of x^2
b is the coefficient of x
c is the constant term

1) Given,

3x^2 - 2x - 1

Finding the discriminant,

➝ D = b^2 - 4ac

➝ D = (-2)^2 - 4 × 3 × (-1)

➝ D = 4 - (-12)

➝ D = 4 + 12

➝ D = 16

2) Solving by using Bhaskar formula,

❒ p(x) = x^2 + 5x + 6 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5\pm \sqrt{( - 5) {}^{2} - 4 \times 1 \times 6 }} {2 \times 1}}}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5 \pm \sqrt{25 - 24} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5 \pm 1}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = - 2 \: or - 3}}}$

❒ p(x) = x^2 + 2x + 1 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm \sqrt{ {2}^{2} - 4 \times 1 \times 1} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm \sqrt{4 - 4} }{2} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm 0}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = - 1 \: or \: - 1}}}$

❒ p(x) = x^2 - x - 20 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - ( - 1) \pm \sqrt{( - 1) {}^{2} - 4 \times 1 \times ( - 20) } }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ 1 \pm \sqrt{1 + 80} }{2} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{1 \pm 9}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = 5 \: or \: - 4}}}$

❒ p(x) = x^2 - 3x - 4 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - ( - 3) \pm \sqrt{( - 3) {}^{2} - 4 \times 1 \times ( - 4) } }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{3 \pm \sqrt{9 + 16} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{3 \pm 5}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = 4 \: or \: - 1}}}$

<u>━━━━━━━━━━━━━━━━━━━━</u>

5 0

3 years ago

Read 2 more answers

Cos(x+y)/cos(x)sin(y)=cot(y)-tan(x)

zhuklara [117]

So there is an identity we'll need to use to solve this:

cos(x+y) = cosxcosy - sinxsiny

replace the numerator with the right hand side of that identity and we get:

(cosxcosy - sinxsiny)/cosxsiny

Separate the numerator into 2 fractions and we get:

cosxcosycosxsiny- sinxsiny/cosxsiny

the cosx's cancel on the left fraction, the siny's cancel on the right fraction and we're left with:

cosy/siny - sinx/cosx

which simplifies to:

coty - tanx

7 0

3 years ago

In Applied Life Data Analysis (Wiley, 1982), Wayne Nelson presents the breakdown time of an insulating fluid between electrodes

ale4655 [162]

Answer:

The sample mean is $\bar{x}=14.371$ min.

The sample standard deviation is $\sigma = 18.889$ min.

Step-by-step explanation:

We have the following data set:

$\begin{array}{cccccccc}0.15&0.82&0.81&1.44&2.70&3.28&4.00&4.70\\4.96&6.49&7.25&8.03&8.40&12.15&31.89&32.47\\33.79&36.80&72.92&&&&&\end{array}$

The mean of a data set is commonly known as the average. You find the mean by taking the sum of all the data values and dividing that sum by the total number of data values.

The formula for the mean of a sample is

$\bar{x} = \frac{{\sum}x}{n}$

where, $n$ is the number of values in the data set.

$\bar{x}=\frac{0.15+0.82+0.81+1.44+2.7+3.28+4+4.7+4.96+6.49+7.25+8.03+8.4+12.15+31.89+32.47+33.79+36.80+72.92}{19}\\\\\bar{x}=14.371$

The standard deviation measures how close the set of data is to the mean value of the data set. If data set have high standard deviation than the values are spread out very much. If data set have small standard deviation the data points are very close to the mean.

To find standard deviation we use the following formula

$\sigma = \sqrt{ \frac{ \sum{\left(x_i - \overline{x}\right)^2 }}{n-1} }$