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2 years ago

Elimination method x+4y=1 -3x-5y=-10

Mathematics

1 answer:

nevsk [136]2 years ago

3 0

Answer:

x = 5 and y = 1 is the answer.

Step-by-step explanation:

(-5)(x+4y=1)

(-4)(-3x-5y=-10)

-5x + -20y = -5

12x + 20y = 40

———————

7x + 0 = 35

7x= 35

7x/7 = 35/7

x = 5

subtitution:

x= 5

x + 4y = 1

5 + 4y = 1

4y = 1 - 5

4y = 4

4y/4 = 4/4

y = 1

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What is 7 divided by 2761 using multiplication to check

zvonat [6]

I'm very confused...... Answer=00253531329

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3 years ago

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Jack ran at 880 ft./min. For the first 10 min. Of the 3 mi. Race before slowing his pace to finish the race with a total time of

Nina [5.8K]

Answer:

Jack ran 704 ft/min during the second half of the race.

Step-by-step explanation:

Here the distance traveled was 3 miles, and the total elapsed time was 20 minutes. Recall that distance = rate * time, or rate = distance / time.

Find the pace (speed, rate) for the second part of the race.

Here, the total distance was 3 miles and the elapsed time 20 minutes. Jack's average speed was thus 3/20 miles/minute. Converting this to feet per minute, we get:

3 mi 5280 ft

------------ * ------------- = 792 ft/min (Jack's average speed)

20 min 1 mi

Recall that the formula for finding the average of x and y is (x + y) / 2.

(1/2)(880 ft/min + p) = 792 ft/min; find p, which represents Jack's pace for the second part of the race.

If (1/2)(880 ft/min + p) = 792 ft/min, and we mult. both sides by 2, we get:

880 ft/min + p = 1584 ft/min.

To solve this for p, subtract 880 ft/min from both sides, obtaining:

p = 704 ft/min

Jack ran 704 ft/min during the second half of the race.

3 0

3 years ago

Solve this using elimination method<br> 5x+25y=60<br> 3x+15y=42

hoa [83]

5x + 25y = 60....multiply by -3
3x + 15y = 42....multiply by 5
-------------------
-15x - 75y = - 180 (result of multiplying by -3)
15x + 75y = 210 (result of multiplying by 5)
-------------------add
0 = 30...incorrect.....this system has no solutions

4 0

2 years ago

The test scores of 32 students are listed below. Construct a boxplot for the data set and include the values of the 5-number sum

zhenek [66]

Answer:

Boxplot is constructed using quartiles and 5 No. summary means including minimum value of data, 1st quartile, 2nd quartile, 3rd quartile and maximum value of data.

As data already in increasing order, we find quartiles using the following formula,

$value\:of\:K_{th}\:Quartile\:,\, Q_k=\:value\:of\:(\frac{k\times{(n+1)}}{4})\,\:th\,observation$

where n = No. of Observations.

∴, 1st Quartile,

$Q_1 = \frac{1\times{(32+1)}}{4}\, th\:\:observation\\\\ \:\:\:=8.25\,th\:observation\\\: \:\:= 8th\,+0.25(9th-8th)\\\:\:\:= 55 + 0.25(57-55)\\\:\:\:= 55.5$

2nd Quartile,

$Q_2 = \frac{2\times{(32+1)}}{4}\, th\:\:observation\\\\ \:\:\:=16.5\,th\:observation\\\: \:\:= 16th\,+0.5(17th-16th)\\\:\:\:= 69 + 0.5(70-69)\\\:\:\:= 69.5$

3rd Quartile,

$Q_3 = \frac{3\times{(32+1)}}{4}\, th\:\:observation\\\\ \:\:\:=24.75\,th\:observation\\\: \:\:= 24th\,+0.75(25th-24th)\\\:\:\:= 79 + 0.75(81-79)\\\:\:\:= 80.5$