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3 years ago

3x+4y=23 and 5x+3y=31. Solve by elimination.

1 answer:

5 0

Let $3x+4y=23$ be equation 1
let $5x+3y=31$ be equation 2

do $(equ1)*3$ and $(equ2)*4$

now $9x+12y=69$
and <u></u> $20x+12y=124$
now eliminate the $y$ by doing $(equ2)-(equ1)$
$11x=55$
$x=5$

now substitute $x=5$ back into equation 1 or 2
$3*(5)+4y=23$
$4y=23-15$
$y=2$

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Select the correct answer.

Marysya12 [62]

Your answer will be A because the absolute value of -7 is 7 that is smaller than 8 8 smaller than 9 and -10 absolute value is 10 so A displayed in the right number sequence

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3 years ago

HELP A.S.A.P!!!! The data to represent average test scores for a class of 16 students includes an outlier value of 78. If the ou

kolezko [41]

When the outlier is removed The mean would increase.

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

Outliers are the value that lies outside the set of data. i.e. the data doesn't fit in the group.

Removing outliers can affect mean more than median. Because outlier removal sometimes affect the median but in a small percentage or sometimes it will remain the same.

Let us prove, consider 16 values one with 78 and other 15 with values nearly 85, 84 that will give the mean value as 84.

78, 84, 82, 86, 84, 85, 83, 86, 82, 85, 84, 83, 86, 85, 86, 85.

Mean = $\frac{Sum of the values}{Number of values}$ .

Mean = $\frac{78+84+82+86+84+85+83+86+82+85+84+83+86+85+86+85}{16}$ .

Mean = $\frac{1344}{16}$ .

Mean = 84.

Remove 78 from the data set then the data set is 84, 82, 86, 84, 85, 83, 86, 82, 85, 84, 83, 86, 85, 86, 85 and number of data is reduced to 15.

Mean = $\frac{84+82+86+84+85+83+86+82+85+84+83+86+85+86+85}{15}$ .

Mean = $\frac{1266}{15}$ .

Mean = 84.4.

The mean is increased.

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3 years ago

Paula finished the race at 2:14 p.m Beatrice finished the race 22 minutes earlier what time did Beatrice finish the race a 1:54

Digiron [165]

Answer: 1:52 PM

Step-by-step explanation:

PAULA: 2:14PM FINISHED THE RACE

BEATRICE: FINISHED 22 MINUTES EARLIER THEN PAULA

YOU TAKE 2:14PM AND SUBTRACT THE 22 MINS BEATRICE RAN TO GET YOU ANSWER.

SO 2:14 -14 MINS=2:00PM 14+8=22 (THE MINS BETRICE FINISHED)

2:00-8 MINS ( REMAINING FROM THE 22 ) THEN 2:00-8 MINS =1:52

ANSWER:1:52PM

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2 years ago

Whats the meaning of Radius?

rodikova [14]

Answer:

The radius is the line from the center of the circle to the side of the circle

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Dado el número N = 4752a, averigua qué valor ha de tomar "a" para que: a) N sea divisible por tres. b) N sea divisible por cinco

lara [203]

Answer:

I will answer it in English:

a) We have te number N = 4752a

if we want to divide it by 3, then the addition of all the digits must be a multiple of 3.

Sum = 4 + 7 + 5 + 2 + a = 6 + 7 + 5 + a = 18 + a

and 18 is a multiple of 3, then we can have, a = 0, a = 3, a = 6, a= 9

b) A number is divisible by 5 if it ends on 5 or 0, so the possible values of a are 0 and 5.

c) we know that 15*3 = 45

then 15*3000= 45000

now we have:

4752a - 45000 = 252a

15*13 = 2520

then we have that a must be equal to zero, and:

15*(13 + 3000) = 47520

d) We want a number that when we divide it by 7, the surpass is 5.

a number is divisible by 7 if the difference between the number without the units and the double of the units is 0 or a multiple of 7.

in N = 4752x the unit is a, then we have:

D = 4752 - 2*x

now, let's choose a such we have a multiple of 7

we know that 5746 is a multiple of 7, so we can choose x= 3 and get:

D = 4752 - 2*3 = 5746

So the number N = 47523 is a multiple of 7, and when we divide it by 7 we will have a surpass of 0.

Then when we divide N + 5 by 7, we will have a surpass of 7.

This is: N + 5 = 47528

This means that the actual value of a that we need is 8.

5 0

3 years ago