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3 years ago

4x + 12 = -7y -y + 12 = 4x Solve with elimination

2 answers:

7 0

$\begin{cases}4x + 12 = -7y \\ -y + 12 = 4x \end{cases} \\ \\\begin{cases}4x + 7y = -12 \\ -4x-y =-12 \end{cases} \\+ ------- \\6y=-24\ \ /:6\\ \\y=-\frac{24}{6}\\ \\y=-4$

$4x+12=-7y\\ \\ 4x+12=-7*(-4)\\ \\4x=28-12\\ \\4x=16\ \ /:4\\ \\x=\frac{16}{4}\\ \\ x=4 \\ \\ \begin{cases}x=4 \\ y=-4 \end{cases}$

statuscvo [17]3 years ago

4 0

Take the second equation and flip it around so the y on the left ends up on the right and the 4x on the right ends up on the left. This makes all negatives positive and all positives negative. -4x + 12 = y

Then add the first equation to the second equation
4x +12 = -7y
-4x + 12 = y this eliminates the x's
24 = - 6y then divide by - 6
- 6 - 6
- 4 = y

So if you know that y = negative 4, you can substitute into either equation. I pick the second one because I am a lazy person.
-y + 12 = 4 x
-(-4) + 12 = 4 x combine your numbers
 16 = 4 x then divide by 4
 4 = x
So your solution is: x = 4 and y = -4 or this is also written (4, -4)

Does that work for you?

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3 years ago

Read 2 more answers

Miguel and three of his friends went to the movies. They originally had a total of $40. Each boy had the same amount of money an

Alenkasestr [34]

Answer:

The money each boy had after buying his ticket is $2.50.

Step-by-step explanation:

Given:

Miguel and three of his friends went to the movies. They originally had a total of $40. Each boy had the same amount of money and spent $7.50 on a ticket.

Now, to find the money each boy had after buying his ticket.

Let the money each boy had after buying his ticket be $x.$

Total number of boys = 4.

Total money they had = $40.

Money each boy spent = $7.50.

Now, to write an equation:

$4(x+7.50)=40$

Now, to solve the equation for getting the money each boy had after buying his ticket:

$4(x+7.50)=40$

$4x+30=40$

Subtracting both sides by 30 we get:

$4x=10$

Dividing both sides by 4 we get:

$x=\$2.50.$

Therefore, the money each boy had after buying his ticket is $2.50.

3 0

3 years ago

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Papessa [141]

Answer:

The equation has the form: y = a + b * x where a and b are constant numbers. The variable x is the independent variable, and y is the dependent variable. Typically, you choose a value to substitute for the independent variable and then solve for the dependent variable.

6 0

3 years ago

CHECK ANSWERS -

Tju [1.3M]

Both are correct.

Good job!

6 0

4 years ago

Find the distance between the points ( - 10,12) and (15,12).

Nitella [24]

The distance formula is:

$d= \sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$

We are given two points in the form (x,y), so plug in the values to the distance formula:

$d= \sqrt{(-10-15)^2-(12-12)^2}$

Next we can simplify. We know that 12-12 is 0, so we can drop it from the equation, as it will not affect our answer. Also, we know that -10-15 is -25:

$d= \sqrt{(-25)^2}$

The square and square root cancel each other out leaving us with 25.

The answer is 25.

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3 years ago