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AlladinOne [14]

3 years ago

11

How many solutions does the system have? \begin{cases} 3x+y=8 \\\\ 2x+2y=8 \end{cases} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ 3x+y=8 2x+2y=8 Choose 1

answer: Choose 1 answer: (Choice A, Checked) A Exactly one solution (Choice B) B No solutions (Choice C) C Infinitely many solutions

1 answer:

ELEN [110]3 years ago

3 0

Answer:

This system has one solution (x=2 and y=2), then the answer is A.

Step-by-step explanation:

The system of equations is:

$3x+y=8$ (1)

$2x+2y=8$ (2)

Let's multiply the first equation by 2 and subtract it to the second equation

$6x-2x+2y-2y=16-8$

$4x=8$

$x=2$

Using this value in (1) we can find y.

$3(2)+y=8$

$6+y=8$

$y=2$

Therefore, this system has one solution (x=2 and y=2), the answer is A.

I hope it helps you!

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Evaluate.<br> 6!4!<br> -----<br> 5!2

solmaris [256]

First one is 6*5*4*3*2*4*3*2

second is 5*4*3*2*2

8 0

3 years ago

Please help me! i will give 10 points and brainliest to those who show their work!!

Black_prince [1.1K]

Hopefully this helps.

8 0

3 years ago

Joe buys groceries for his grandfather the groceries cost $42 plus 5% tax joe wants to know the total cost of the groceries incl

vekshin1

<h3>Answer: $44.10</h3>

====================================================

Work Shown:

5% = 5/100 = 0.05

5% of 42 = 0.05*42 = 2.10

tax = $2.10

total cost including tax = $42 + $2.10 = $44.10

----------

An alternative is to multiply 42 by 1.05 to get

1.05*42 = 44.10

We get the same answer. The 1.05 refers to 1 + 0.05 where the "1" is 100% and the 0.05 is 5%, so the two combine to 105%, meaning the total cost is 105% of the cost before tax is considered.

7 0

3 years ago

Write the equation -4x^2+9y^2+32x+36y-64=0 in standard form. Please show me each step of the process!

IgorC [24]

Hey there, hope I can help!

$-4x^2+9y^2+32x+36y-64=0$

$\mathrm{Add\:}64\mathrm{\:to\:both\:sides} \ \textgreater \ 9y^2+32x+36y-4x^2=64$

$\mathrm{Factor\:out\:coefficient\:of\:square\:terms} \ \textgreater \ -4\left(x^2-8x\right)+9\left(y^2+4y\right)=64$

$\mathrm{Divide\:by\:coefficient\:of\:square\:terms:\:}4$
$-\left(x^2-8x\right)+\frac{9}{4}\left(y^2+4y\right)=16$

$\mathrm{Divide\:by\:coefficient\:of\:square\:terms:\:}9$
$-\frac{1}{9}\left(x^2-8x\right)+\frac{1}{4}\left(y^2+4y\right)=\frac{16}{9}$

$\mathrm{Convert}\:x\:\mathrm{to\:square\:form}$
$-\frac{1}{9}\left(x^2-8x+16\right)+\frac{1}{4}\left(y^2+4y\right)=\frac{16}{9}-\frac{1}{9}\left(16\right)$

$\mathrm{Convert\:to\:square\:form}$
$-\frac{1}{9}\left(x-4\right)^2+\frac{1}{4}\left(y^2+4y\right)=\frac{16}{9}-\frac{1}{9}\left(16\right)$

$\mathrm{Convert}\:y\:\mathrm{to\:square\:form}$
$-\frac{1}{9}\left(x-4\right)^2+\frac{1}{4}\left(y^2+4y+4\right)=\frac{16}{9}-\frac{1}{9}\left(16\right)+\frac{1}{4}\left(4\right)$

$\mathrm{Convert\:to\:square\:form}$
$-\frac{1}{9}\left(x-4\right)^2+\frac{1}{4}\left(y+2\right)^2=\frac{16}{9}-\frac{1}{9}\left(16\right)+\frac{1}{4}\left(4\right)$

$\mathrm{Refine\:}\frac{16}{9}-\frac{1}{9}\left(16\right)+\frac{1}{4}\left(4\right) \ \textgreater \ -\frac{1}{9}\left(x-4\right)^2+\frac{1}{4}\left(y+2\right)^2=1$

$Refine\;once\;more\;-\frac{\left(x-4\right)^2}{9}+\frac{\left(y+2\right)^2}{4}=1$

For me I used
$\frac{\left(y-k\right)^2}{a^2}-\frac{\left(x-h\right)^2}{b^2}= 1$
$As\;\mathrm{it\;\:is\:the\:standard\:equation\:for\:an\:up-down\:facing\:hyperbola}$

I know yours is an equation which is why I did not go any further because this is the standard form you are looking for. I would rewrite mine to get my hyperbola standard form. However the one I have provided is the form you need where mine would be.
$\frac{\left(y-\left(-2\right)\right)^2}{2^2}-\frac{\left(x-4\right)^2}{3^2}=1$

Hope this helps!

4 0

3 years ago

Find the commission.

juin [17]

Answer:

63.9

Step-by-step explanation:

Convert 9% to a decimal: 0.09

710×.09=63.9

Please give me brainliest

3 0

3 years ago