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BlackZzzverrR [31]
3 years ago
14

–7x + 8y = 1

Mathematics
2 answers:
Mademuasel [1]3 years ago
8 0

Answer: -6

Step-by-step explanation:

First, try deleting the x-coordinate from the equations by making them the same number. By doing that I multiplied the first equation (-7x+8y=1) by 4 and (4x-8y=20) by 7. That got me -28x+32y=4 and +28x-56y=140. You could cross out the 28 which gets +32y=4 and -56y=140. Then add up both equations. It’s gets you -24y=144

-24y=144

—————— then divide by -24

-24 -24

144/-24=-6

Hope this helped!

Step2247 [10]3 years ago
4 0

\bf \begin{cases} -7x+8y=1\\ 4x-8y=20 \end{cases}\qquad \qquad \stackrel{\textit{using elimination}}{ \begin{array}{llll} -7x~~\begin{matrix} +8y \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~=1\\ ~~4x~~\begin{matrix} -8y \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~=20\\ \cline{1-1}\\ -3x~\hfill =21 \end{array}}

\bf x=\cfrac{21}{-3}\implies \blacktriangleright x=-7 \blacktriangleleft \\\\\\ \stackrel{\textit{substituting in the 2nd equation}}{4(-7)-8y=20}\implies -28-8y=20\implies -8y=48 \\\\\\ y=\cfrac{48}{-8}\implies \blacktriangleright y = -6 \blacktriangleleft

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Step-by-step explanation:

\frac{(x - 2) {}^{2} }{4}  +  \frac{(y + 5) {}^{2} }{9}  = 1

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where c is

Our center (h,k) is (2, -5)

{c}^{2}  =  {a}^{2}  -  {b}^{2}

Here a^2 is 9, b^2 is 4.

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6 0
1 year ago
Somebody please help​
iren [92.7K]

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Yes, No, No, No

Step-by-step explanation:

To decide whether the point lies on the circle, what you need to do it simply substituting the x and y values into the equation and check if it add up to be 25

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5 0
3 years ago
What is 7 devided by 245 and show work
agasfer [191]

1. <span>Set up the long division.
</span>
<span>245/7</span>

2. <span>Calculate 700 ÷ 245, which is 2 with a remainder of 210.
</span>
<span><span>0.02</span><span>245/7.</span><span>4.90</span><span>2.10</span></span>

3. <span>Bring down 0, so that 2100 is large enough to be divided by 245.
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<span><span>0.02</span><span>245|/.</span><span>4.90</span><span>2.100</span></span>

4. <span>Calculate 2100 ÷ 245, which is 8 with a remainder of 140.
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<span><span>0.028</span><span>245|/.</span><span>4.90</span><span>2.100</span><span>1.960</span><span>140</span></span>

5. <span>Bring down 0, so that 1400 is large enough to be divided by 245.
</span>
<span><span>0.028</span><span>245/7.</span><span>4.90</span><span>2.100</span><span>1.960</span><span>1400</span></span>
6. <span>Calculate 1400 ÷ 245, which is 5 with a remainder of 175.
</span>
<span><span>0.0285</span><span>245|7.</span><span>4.90</span><span>2.100</span><span>1.960</span><span>1400</span><span>1225</span><span>175</span></span>

7. <span>Therefore, 7 divided by 245 approximately equals 0.0285
</span><span><span>7÷245≈0.0285</span></span>

8. <span>Simplify
</span><span><span><span>0.0285  <------------- Answer :) </span></span>
</span>

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