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2 years ago

Solve system of equation using elimination by addition. Will give brainliest!!

Mathematics

1 answer:

DedPeter [7]2 years ago

5 0

Answer:

$x = 2, y = -3$

Step-by-step explanation:

Add the 2 equations together, then solve for x.

$(2x + 2y) + (3x - 2y) = (-2) + (12)\\ 2x + 3x + 2y - 2y = -2 + 12\\5x = 10\\x = 2$

Now that we know the value of x, we can easily find y by substitution.

$3x - 2y = 12\\3(2) - 2y = 12\\6 - 2y = 12\\-2y = 6\\y = -3$

These are the answers

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Plz help I will post the other 3 questions after these are answered I will be giving the brainiest plz help would really appreci

Nadusha1986 [10]

Answer for #1:

The number of square tiles required to cover the bathroom floor is approximately 31.

Answer for #2:

2/3

7 0

2 years ago

Which expression represents the sum of (2x - 5y) and (x + y)

Hatshy [7]

Answer:

-10y

Step-by-step explanation:

6 0

3 years ago

What is “One third of the opposite of a number is less than 12?”

nirvana33 [79]

Answer:

$\frac{1}{3}(-x)$ <12

4 0

3 years ago

Me. Ellis is a teacher who tutors after school. Of the students he tutors, 30% need help in computer science and 70% need assist

Anna11 [10]

Answer: There are 82.5% after school students who are enrolled in his classes.

Step-by-step explanation:

Let the total number of students be 100

Percentage of students who need help in computer science = 30%

So, number of students who need help in computer science = 30

Percentage of students who need help in maths = 70%

So, number of students who need assistance in maths = 70

Of the students who need help,

40% are enrolled in Mr. Ellis's class during the school day,

So, it means 60% are enrolled in his class after the school day.

Number of students who are enrolled in his class after the school day = 60

Number of students who need help in Maths is given by

$\frac{70}{100}\times 60=42$

Of the students that need help in maths, percent of students are enrolled in his class during the day = 25%

So, number of students who need help in maths and enrolled in his class after school hours

$\frac{75}{100}\times 42=31.5$

Number of students who need help in computer science and enrolled in his class after school hours

$\frac{30}{100}\times 60=18$

Therefore, there are $31.5+18=49.5$ students who joined his class after school hours,

Percentage of the after students who are enrolled in Mr. Ellis's classes is given by

$\frac{49.5}{60}\times 100=82.5\%$

Hence, there are 82.5% after school students who are enrolled in his classes.

6 0

4 years ago

Solve the following systems of equations: 4x+5y=-4 4x+3y=12 X=? Y=?

Mrac [35]

For this case we have the following system of equations:

$4x + 5y = -4\\4x + 3y = 12$

We multiply the second equation by -1:

$-4x-3y = -12$

We add the equations:

$4x-4x + 5y-3y = -4-12\\5y-3y = -4-12\\2y = -16\\y = \frac {-16} {2}\\y = -8$

We find the value of "x":

$4x = 12-3y\\x = \frac {12-3y} {4}\\x = \frac {12-3 (-8)} {4}\\x = \frac {12 + 24} {4}\\x = \frac {36} {4}\\x = 9$

Thus, the solution of the system is given by:

$(x, y) :( 9, -8)$

ANswer:

(9, -8)

7 0

3 years ago

Read 2 more answers