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3 years ago

2(x-3) = (x-1) + 7 Please show your steps!!

Mathematics

2 answers:

melamori03 [73]3 years ago

7 0

2(x-3)=(x-1)+7
2x-6=x+6
x=12. Hope it help!

andre [41]3 years ago

6 0

Simplify the equation.

First, distribute the 2 in the left side of the equation.
Resulting in: 2x-6 = (x-1) + 7

Second, remove the parentheses form the right side of the equation (there is nothing to distribute there).
Resulting in: x - 1 + 7

Now simplify the right side of the equation by subtracting the 1 from the 7.
Resulting in: x + 6

Our goal is to isolate the x to the left side, and the numerals to the right side.
With that in mind, add the 6 (from the right side) to both sides. This cancels out the 6 on the right side.
Resulting in: 2x = 12

Lastly, in order to fully isolate the variable (x), we divide both sides by 2.
Resulting in: x = 6

Hope this helps.

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Please help me this is a study island question!

algol13

Answer:

It's C

Step-by-step explanation:

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7 0

3 years ago

For which function is f(x) equal to f^1(x) ( answer choices in picture )

Sonja [21]

Answer:

C. $f(x)=\frac{x+1}{x-1}$

Step-by-step explanation:

Let's find the inverse of each of the given options.

Option A:

$f(x)=\frac{x+6}{x-6}\\y=\frac{x+6}{x-6}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+6}{y-6}$

Rewrite in terms of 'y'. This gives,

$x(y-6)=y+6\\xy-6x=y+6\\xy-y=6x+6\\y=\frac{6x+6}{x-1}$

The given function $y=\frac{6x+6}{x-1}\ne y=\frac{x+6}{x-6}$

So, option A is incorrect.

Option B:

$f(x)=\frac{x+2}{x-2}\\y=\frac{x+2}{x-2}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+2}{y-2}$

Rewrite in terms of 'y'. This gives,

$x(y-2)=y+2\\xy-2x=y+2\\xy-y=2x+2\\y=\frac{2x+2}{x-1}$

The given function $y=\frac{2x+2}{x-1}\ne y=\frac{x+2}{x-2}$

So, option B is incorrect.

Option C:

$f(x)=\frac{x+1}{x-1}\\y=\frac{x+1}{x-1}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

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

Rewrite in terms of 'y'. This gives,

$x(y-1)=y+1\\xy-x=y+1\\xy-y=x+1\\y=\frac{x+1}{x-1}$

The given function $y=\frac{x+1}{x-1}\ equals\ y=\frac{x+1}{x-1}$

So, option C is correct.

Option D:

$f(x)=\frac{x+5}{x-5}\\y=\frac{x+5}{x-5}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+5}{y-5}$

Rewrite in terms of 'y'. This gives,

$x(y-5)=y+5\\xy-5x=y+5\\xy-y=5x+5\\y=\frac{5x+5}{x-1}$

The given function $y=\frac{5x+5}{x-1}\ne y=\frac{x+6}{x-6}$

So, option D is incorrect.

Therefore, only option C is correct.

7 0

3 years ago

Sarah answered 24 questions on her test correctly and earned an 80%. How many questions were on the test?

MaRussiya [10]

Answer:

43 questions in total

Step-by-step explanation:

the original equation with the unknown (total number of questions on the test) will look like this

$\frac{total \: number \: of \: questions \: on \: exam}{24 \: answered \: questions} = 80\%$

we know this because to work out a percentage in the 1st place you need the total ÷ number (in this case it's ÷ how many questions out of the total she did answer)

now you rearrange.

you need to move the 24 to get the total on it's own here's how you do it

$\frac{tot \: num \: of \: qs}{24} \times 24 = 80\% \times 24$