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3 years ago

Drag the tiles to the correct boxes to complete the pairs. Match the systems of equations with their solutions.

Mathematics

2 answers:

devlian [24]3 years ago

6 0

<h3>Answer:</h3>

4, 1, 2, 3 . . . . . the systems of equations corresponding to the given solutions, in order

<h3>Step-by-step explanation:</h3>

When there are this many to do, it is convenient to let a calculator or spreadsheet help. Most will work best with integer coefficients, so the pairs of equations can be written ...

x - y = 25
2x + 3y = 180 . . . solution (51, 26)

2x - 3y = -5
11x + y = 550 . . . solution (47, 33)

x - y = 19
-12x + y = 168 . . . solution (-17, -36)

4. Here, we have a problem. The given equations don't match any solutions. The only remaining solution is (-31, -56), and it gives a value of -6 for the first equation, not 6. The second equation needs parentheses to make it work. We think your problem is ...

... 2x -y = -6, (x -305)/3 = 2y

Recast the way the others are above, these equations become ...

2x - y = -6
x - 6y = 305 . . . solution (-31, -56)

_____

<em>Comment on solution to systems of equations</em>

The solution to ...

ax +by = c
dx +ey = f

is ...

x = (bf -ec)/(bd -ea)
y = (cd -a·f)/(bd -ea) . . . . . (same denominator as for x)

This is a modified form of Cramer's rule. It is modified in that both numerator and denominator have the terms swapped (are the negative of the terms in the classic Cramer's rule). This form can be easy to remember, as the pattern is fairly simple. (Look at where the coefficients are in the equations. Use your spatial memory to remember the pattern.)

<u>Example</u>:

Applying these solution equations to system (4), we have ...

... x = ((-1)·305 -(-6)(-6))/((-1)·1 -(-6)·2) = -341/11 = -31

... y = ((-6)·1 -305·2) = -616/11 = -56

Lera25 [3.4K]3 years ago

6 0

Answer:

Step-by-step explanation:

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iren2701 [21]

Answer:

for Lena

C = 3x C + 5x

for Patrick

C = 9x C = 10x

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Step-by-step explanation:

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2 years ago

Let represent the number of tires with low air pressure on a randomly chosen car. The probability distribution of is as follows.

Sindrei [870]

Answer:

a) $P(X=3) = 0.1$

b) $P(X\geq 3) =1-P(X$

And replacing we got:

$P(X \geq 3) = 1- [0.2+0.3+0.1]= 0.4$

c) $P(X=4) = 0.3$

d) $P(X=0) = 0.2$

e) $E(X) =0*0.2 +1*0.3+2*0.1 +3*0.1 +4*0.3= 2$

f) $E(X^2)= \sum_{i=1}^n X^2_i P(X_i)$

And replacing we got:

$E(X^2) =0^2*0.2 +1^2*0.3+2^2*0.1 +3^2*0.1 +4^2*0.3= 6.4$

And the variance would be:

$Var(X0 =E(X^2)- [E(X)]^2 = 6.4 -(2^2)= 2.4$

And the deviation:

$\sigma =\sqrt{2.4} = 1.549$

Step-by-step explanation:

We have the following distribution

x 0 1 2 3 4

P(x) 0.2 0.3 0.1 0.1 0.3

Part a

For this case:

$P(X=3) = 0.1$

Part b

We want this probability:

$P(X\geq 3) =1-P(X$

And replacing we got:

$P(X \geq 3) = 1- [0.2+0.3+0.1]= 0.4$

Part c

For this case we want this probability:

$P(X=4) = 0.3$

Part d

$P(X=0) = 0.2$

Part e

We can find the mean with this formula:

$E(X)= \sum_{i=1}^n X_i P(X_i)$

And replacing we got:

$E(X) =0*0.2 +1*0.3+2*0.1 +3*0.1 +4*0.3= 2$

Part f

We can find the second moment with this formula

$E(X^2)= \sum_{i=1}^n X^2_i P(X_i)$

And replacing we got:

$E(X^2) =0^2*0.2 +1^2*0.3+2^2*0.1 +3^2*0.1 +4^2*0.3= 6.4$

And the variance would be:

$Var(X0 =E(X^2)- [E(X)]^2 = 6.4 -(2^2)= 2.4$

And the deviation:

$\sigma =\sqrt{2.4} = 1.549$

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V125BC [204]

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Read 2 more answers

Find the z score that has 70.54% of the distribution area to its right

Alik [6]

The z score that has 70.54% of the distribution area is 9.92

<h3>What is a z-score?</h3>

The z-score is a numerical measurement used in statistics to refer to how much a given value differs from the standard deviation.

For the random variable x, the z-score is;

z = (x - 11)/2

therefore, 70.54% of the area under the curve lies to the right of x,

then the area to the left of x is;