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2 years ago

10

Simplify using the distributive property, Show all work (-2x - 9)(-4).

1 answer:

fgiga [73]2 years ago

6 0

-2x(-4)=8x
-9(-4)=36
8x+36 is the answer

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Plz give correct answer! (might give brainliest) :)<br><br><br> thnx, have a nice day!

neonofarm [45]

Answer:

56

Step-by-step explanation:

(14-7)×(40-32)

(7)×(8)

56

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3 years ago

Read 2 more answers

At a Psychology final exam, the scores are normally distributed with a mean 73 points and a standard deviation of 10.6 points. T

USPshnik [31]

Answer:

The score that separates the lower 5% of the class from the rest of the class is 55.6.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

$\mu = 73, \sigma = 10.6$

Find the score that separates the lower 5% of the class from the rest of the class.

This score is the 5th percentile, which is X when Z has a pvalue of 0.05. So it is X when Z = -1.645.

$Z = \frac{X - \mu}{\sigma}$

$-1.645 = \frac{X - 73}{10.6}$

$X - 73 = -1.645*10.6$

$X = 55.6$

The score that separates the lower 5% of the class from the rest of the class is 55.6.

3 0

3 years ago

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julia-pushkina [17]

Answer:

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2 years ago

Find two fractions with a product between 10 and 11

Eva8 [605]

10.5 i’am not sure but I think

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3 years ago

Solve with cramer's rule x+2y+3z=11, 2x+y+2z=10, 3x+2y+z=9

nalin [4]

Answer:

x = 2 , y = 0 , z = 3

Step-by-step explanation:

Cramer's rule is a rule through which we can find the solution of linear equation.

we have the three linear equations as

x+2y+3z=11

2x+y+2z=10

3x+2y+z=9

AX=B

A: coefficient matrix

X= unknown vectors(x,y,z)

D = values of the linear equation (11 , 10 , 9)

now we find the determinant of the given linear equation

determinant of the matrix will be

A = $\left[\begin{array}{ccc}1&2&3\\2&1&2\\3&2&1\end{array}\right]$ = 1(1-4) - 2(2-6) + 3(4 - 3)

= 1(-3) - 2(-4) + 3(1)

= -3+8+3 = 8

also D $\neq 0$

so the determinant is Non zero we can apply Cramer's rule

we will be replacing the first column of the coefficient matrix A with the values of D

by replacing the first column we will get the value of the variable 'x'

Dx = $\left[\begin{array}{ccc}11&2&3\\10&1&2\\9&2&1\end{array}\right]$ = 11(1-4) -2(10-18) + 3(20-9) = -33+16+33 = 16

x = $\frac{Dx}{D}$ = $\frac{16}{8}$ = 2

similarly

Dy = $\left[\begin{array}{ccc}1&11&3\\2&10&2\\3&9&1\end{array}\right]$ = 1(10-18) -11(2-6) + 3(18 -30) = -8 +44 -36 = 0

y = $\frac{Dy}{D}$ = 0

Dz= $\left[\begin{array}{ccc}1&2&11\\2&1&10\\3&2&9\end{array}\right]$ = 1(9 - 20) -2(18 - 30) + 11(4 -3) = -11 +24 +11 = 24

z = $\frac{Dz}{D}$ = $\frac{24}{8} = 3$

so we have the solution as

x = 2 , y = 0 , z = 3

Therefore the solution for the given linear equations is (2,0,3).

3 0

2 years ago