All categories

3 years ago

Solve the following pairs of simultaneous equations.

Mathematics

1 answer:

Sergeeva-Olga [200]3 years ago

3 0

Answer and step-by-step explanation:

a) -4x + 5y = -9 (2)

2x + 3y = 21

Multiply the second equation by 2, you will get:

4x + 6y = 42 (1)

Use (1) plus with (2), you will get:

4x + (-4x) + 6y + 5y = -9 + 42

11y = 33

y = 33/11

y = 3

4x + 18 = 42

4x = 24

x = 6

b) 2x + 5y = -6

3x + 2y = 2

Multiply first equation by 3, you will get:

6x + 15y = -18 (1)

Multiply the second equation by 2 and you will get:

6x + 4y = 4 (2)

Subtract (1) by (2), we got:

6x -6x + 15y - 4y = -18 - 4

11y = -22

y = -22/11

y = -2

6x + 4y = 4

6x -8 = 4

6x = 12

x = 2

c) 2x - 2y = -4

5x + 4y = 17 (2)

Multiply the first euation by 2, we got:

4x - 4y = -4 (3)

Use (3) minus for (2), we get:

4x - 5x -4y + 4y = -4 - 17

-x = -21

x = 21

4x - 4y = -4

84 - 4y = -4

-4y = -4 + 84

-4y = 80

y = 80 / -4

y = -20

d) 2x - 3y = 6

4x - 5y = 9 (1)

Multiply the first equation by 2, we got:

4x - 6y = 12 (2)

Use (1) minus for (2), we got:

4x -4x - 5y - 6y = 9 -12

-11y = -3

y = -3/-11

y = 3/11

2x - 3y = 6

2x - 9/11 = 6

2x = 66/11 + 9/ 11

2x = 75/11

x = 75/11 * 1/2

x = 75 / 22

e) x/2 + y/3 = 2

x/4 + y/3 = 4

Use the first equation subtract the second equation, we got:

x/2 - x/4 + y/3 - y/3 = 2 - 4

2x/4 -x/4 = -2

x/ 4 = -2

x = -2 * 4

x = -8

x/2 + y/3 = 2

-8 / 2 + y/3 = 2

y / 3 = 2 + 4

y/3 = 6

y = 6*3

y = 18

f) x/3 + y/2 = 3/2 (1)

x/2 + y/5 = -1/2 (2)

I don't know how to solve this, sr

Hope this helped :3

You might be interested in

2. The radius of a circle is 9 cm. Find the area of the circle

MatroZZZ [7]

Answer:

Area of a Circle = 254.34 cm²

Step-by-step explanation:

Area of a Circle = π r²

Area of a Circle = 3.14 * 9²

Area of a Circle = 254.34 cm²

3 0

3 years ago

What is the awnser to the circled equations?

pshichka [43]

Answer:

$y = - \frac{1}{3}x - 1$

Step-by-step explanation:

We have to write an equation of a line which passes through the given point (-9,2) and is perpendicular to the given straight line y = 3x - 12 ........... (1)

Now, equation (1) is in the slope-intercept form and the slope of the line is 3.

Let, m is the slope of the required line.

So, 3m = -1

{Since, the product of the slopes of two perpendicular straight lines is -1}

⇒ $m = - \frac{1}{3}$

Therefore, the equation of the required line in slope intercept form is

$y = - \frac{1}{3} x + c$ {Where c is a constant}

Now, this above equation passes through the point (-9,2) point.

So, $2 = - \frac{1}{3} \times (-9) + c$

⇒ 2 = 3 + c

⇒ c = - 1

Therefore, the equation of the required straight line is $y = - \frac{1}{3}x - 1$ (Answer)

5 0

4 years ago

A diver begins at sea level and dives down 200 feet. He ascends at a steady rate of 12 and one-third feet per minute for 4. 5 mi

dexar [7]

The diver's depth is 55.485 feet.

Option B represents the correct expression of the equation.

<h2>How do you express the given condition in an equation form?</h2>

Given that the total depth is 200 feet. the steady rate of the diver is 12 and one-third feet per minute. The total time taken by the diver is 4.5 minutes.