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Talja [164]
3 years ago
7

I need help... I don't m is how to do this

Mathematics
2 answers:
Rama09 [41]3 years ago
6 0
U have to find what is x to find the y
amid [387]3 years ago
3 0
4)

\begin{cases}
x-2y=10\\
\frac{1}{2}x-2y=4
\end{cases}\\\\
-----------------------------\\\\
\textit{now, we solve for the 1st equation for either, in this case, "y"}\\\\
x-2y=10\implies -2y=10-x\implies y=\cfrac{10-x}{-2}\implies \boxed{y}=\cfrac{x}{2}-5\\\\
-----------------------------\\\\
\textit{and we use that "y" from the 1st one, IN the 2nd one}\\\\
\cfrac{1}{2}x-2\boxed{y}=4\implies \cfrac{1}{2}x-2\left(  \boxed{\cfrac{x}{2}-5}\right)=4
\\\\\\


\bf \cfrac{x}{2}-2\cdot \cfrac{x}{2}-2\cdot -5=4\implies \cfrac{x}{2}-x+10=4
\\\\\\
\textit{now, we multiply both sides by 2, to do away with the denominator}\\\\
2\left( \cfrac{x}{2}-x+10 \right)=2\cdot 4\implies x-2x+20=8
\\\\\\
-x=-12\implies 12=x

solving for either variable on either equation, and using that equivalent on the other, is "substituting" the variable in the other equation, thus is called "substitution"

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Jacob has $200 to spend on STAR WARS toys. He already purchased $75 on vehicles and new action figures will cost him $8 each. Ho
just olya [345]

Answer:

15 action figures

Step-by-step explanation:

Jacob had $200 to start off with. He spent $75 on vehicles, so we are going to subtract $75 from $200

200 - 75 = 125

He had $125 left. From the money he has left, he wants to purchase more toys. Action figures are $8 each. We will need to find how many action figures he can buy with the rest of his money. To do that, we will divide $125 by $8

125/8 = 15.625

He can buy 15 action figures with his remaining money. He will have remaining change.

I think the equation is:

8x + 125 = 200

8 gets the variable, 200 is the total, and 125 will not get the variable.

6 0
3 years ago
The sum of two books and a pencil is $6.00. The difference of cost between 3 books and 2 pencils is $ 2.00. Find the cost of a b
Gala2k [10]

Answer:

The book costs $2 and the pencil also costs $2.

Step-by-step explanation:

It is easy to get the value of the book and the pencil if we use<em> algebraic expressions.</em>

Let x be the cost of the book and let y be the cost of the pencil.

The sum of 2 books and a pencil is $6.00

  • 2x + y = $6.00

The difference of cost between 3 books and 2 pencils is $2.00.

  • 3x - 2y = $2.00

Step 1: Let's get the value of y first.

2x + y = 6

y = 6 - 2x

Step 2: Let's substitute the value of y and look for the value of x.

3x - 2y = $2.00

3x - 2(6-2x) = 2

3x - 12 + 4x = 2

7x = 12 + 2

7x = 14

x = \frac{14}{7}

x = $2 (this is the cost of the book)

Step 3: Let's substitute the value of x and look for the value of y.

2x + y = 6

2 (2) + y = 6

4 + y = 6

y = 6 - 4

y = $2 (this is the cost of the pencil)

Let's check:

2x + y = $6

2(2) + 2 = 6

4 + 2 = 6

6 = 6<em> (CORRECT)</em>

<em></em>

8 0
3 years ago
An expression is shown below:
ivann1987 [24]

Answer:

It is irrational and equal to 5 times the square root of 2.

Step-by-step explanation:

The statement that is true about the expression:

( √(32) ) + √2

( √(16 * 2) ) + √2

( √(4²) *√2 ) + √2

( 4 *√2 ) + √2

( √2+√2+√2+√2 ) + √2

...and this is ( 4 ) + 1 times √2

The answer is 5 times √2

So the expression is irrational and equal to 5 times the square root of 2.

4 0
3 years ago
Read 2 more answers
A ladder is 59 inches tall. How tall is it in feet and inches?
MrRissso [65]
4 Feet and about 9 inches
6 0
3 years ago
Read 2 more answers
A Geiger counter counts the number of alpha particles from radioactive material. Over a long period of time, an average of 14 pa
UkoKoshka [18]

Answer:

0.2081 = 20.81% probability that at least one particle arrives in a particular one second period.

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}

In which

x is the number of sucesses

e = 2.71828 is the Euler number

\mu is the mean in the given interval.

Over a long period of time, an average of 14 particles per minute occurs. Assume the arrival of particles at the counter follows a Poisson distribution. Find the probability that at least one particle arrives in a particular one second period.

Each minute has 60 seconds, so \mu = \frac{14}{60} = 0.2333

Either no particle arrives, or at least one does. The sum of the probabilities of these events is decimal 1. So

P(X = 0) + P(X \geq 1) = 1

We want P(X \geq 1). So

P(X \geq 1) = 1 - P(X = 0)

In which

P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}

P(X = 0) = \frac{e^{-0.2333}*(0.2333)^{0}}{(0)!} = 0.7919

P(X \geq 1) = 1 - P(X = 0) = 1 - 0.7919 = 0.2081

0.2081 = 20.81% probability that at least one particle arrives in a particular one second period.

8 0
4 years ago
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