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Lemur [1.5K]
2 years ago
15

12x + 15y = 9−12x − 18y = −6 PLEASE I NEED EXPLANATION THANKS

Mathematics
1 answer:
Rama09 [41]2 years ago
7 0

Answer:

<u><em>x</em></u><u> = 2</u>

<em><u>y</u></em><u> = –1</u>

Step-by-step explanation:

We need to solve this system of equations for the point where the two linear equations intersect. That means solving for <em>one</em> variable, then using that to solve for the other. But, I'm looking at this, and...

Well, I see an easy way to isolate <em>y</em> right now! See how one equation has <u>12</u><em><u>x</u></em> and the other has <u>–</u><u>12</u><u><em>x</em></u>? Adding the two equations together will cancel them out!

That gives us this equation:

12<em>x</em> – 12<em>x</em> + 15<em>y</em> – 18<em>y</em> = 9 – 6  — adding the expressions together

15<em>y</em> – 18<em>y</em> = 9 – 6  — cancel out the 12<em>x</em>

–3<em>y</em> = 3  — simplify the equation

–3<em>y</em> ÷ 3 = 3 ÷ 3  — divide by 3 to isolate <em>y</em>

<em>y</em> = –1  — simplify the equation

Now that we have our <em>y</em>-value, we can substitute into the equation and solve for <em>x</em>. I'm substituting into both to make sure <em>y</em> = –1 is part of the solution point (on a coordinate plane, this is where the functions intersect).

12<em>x</em> + 15<em>y</em> = 9  — original equation

12<em>x</em> + 15(–1) = 9  — substitute –1 for <em>y</em>

12<em>x</em> – 15 = 9  — simplify

12<em>x</em> – 15 + 15 = 9 + 15  — add 15 on both sides to isolate 12<em>x</em>

12<em>x</em> = 24  — simplify

12<em>x</em> ÷ 12 = 24 ÷ 12   — divide by 12 on both sides to isolate <em>x</em>

<em>x</em> = 2  — simplify

That's <em>one</em> equation. Let's check the other with these values to <em>make sure</em> (2, –1) is the solution point.

–12<em>x</em> – 18<em>y</em> = –6

–12(2) – 18(–1) ≟ –6

18 – 24 ≟ –6

–6 = –6 ✓

Yep, this is the solution we're looking for!

Hope this helps you understand the concept! Have a great day!

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2 years ago
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Need help <br><br> Pls explain
Crank

Given:

The graph of a line.

To find:

The equation of the line.

Solution:

From the given graph, it is clear that the line passes through the points (0,-2) and (-6,8). So, the equation of the line is:

y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)

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Subtract 2 from both sides.

y=-\dfrac{5}{3}x-2

Therefore, the equation of the line is y=-\dfrac{5}{3}x-2.

7 0
3 years ago
A square mirror has sides measuring 2 ft less than the sides of a square painting. If the difference between their areas is 32 f
kari74 [83]

Answer:  The side lengths of mirror and painting are 7 ft and 9 ft respectively.

Step-by-step explanation:  Given that a square mirror has sides measuring 2 ft less than the sides of a square painting and the difference between their areas is 32 ft.

We are to find the lengths of the sides of the mirror and the painting.

Let x ft represents the length of the side of mirror. Then, the side length of square painting is (x+2) ft.

According to the given information, we have

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Therefore, the side length of mirror is 7 ft and the side length of painting is (7+2) = 9 ft.

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5 0
3 years ago
15 points and brainliest!! please help !!
Arte-miy333 [17]
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