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3 years ago

Solve using elimination PLEASE I NEED HELP!!! IT WOULD REALLY MEAN A LOT IF ANYONE CAN ANSWER THIS! 16 POINTS!!!

Mathematics

1 answer:

Marysya12 [62]3 years ago

4 0

Answer:

(x, y) = (2, -3/4)

Step-by-step explanation:

The point of the "elimination" technique is to combine the equations in a way that eliminates one of the variables. Sometimes this involves multiplying one or both of the equations by constants before you add those results together. In any event, the first step is to look at the coefficients of the variable terms to see if there is a simple combination of them that will result in zero.

The y terms have coefficients that are opposites of each other (4, -4), so you can simply add the two equations to eliminate y as a variable.

(2x +4y) +(x -4y) = (1) +(5)

3x = 6 . . . . . simplify

x = 2 . . . . . . divide by 3

Now, you find y by substituting this value into one of the equations. I would choose the equation with the positive y-coefficient:

2(2) +4y = 1

4y = -3 . . . . . . subtract 4

y = -3/4

Then the solution is ...

(x, y) = (2, -3/4)

_____

A graphing calculator confirms this solution.

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A winery has a vat with two pipes leading to it. The inlet pipe can fill the vat in 5 hours, while the outlet pipe can empty it

Rashid [163]

Answer:

$time=40/3hours\approx 13.3hours$

Step-by-step explanation:

The rates are additive: you can calculate the inlet rate and the outlet rate and add them algebraically, i.e. the inlet rate will be positive and the outlet rate will be negative.

1. Inlet rate:

$1vat/5hours$

2. Outlet rate:

$1vat/8hours$

3. Net rate:

$\text{Inlet rate - outlet rate}=1vat/5hours-1vat/8hours\\\\ \text{Net rate}=(8-5)vat/40hour=3vat/40hour=(3/40)vat/hour$

4. Time to fill the vat

$rate=amount/time\implies time=amount/rate\\ \\ time=1vat/(3vat/40hour)$

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2 years ago

What is the value of (8 – 5)!?

Lubov Fominskaja [6]

$(8-5)!=3!=6$

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3 years ago

Given the following system of equations: 2x + 6y = 12 4x + 3y = 15 Which action creates an equivalent system that will eliminate

ozzi

Answer:

Multiply the second equation by −2 to get −8x − 6y = −30.

Step-by-step explanation:

{2x + 6y = 12

{4x + 3y = 15

{2x + 6y = 12

{−8x − 6y = −30 >> New Equation

* Doing this will give you additive inverses of −6y and 6y, which result in 0, so they are both ELIMINATED.

** [3, 1] is your solution.

I am joyous to assist you anytime.

6 0

3 years ago

Read 2 more answers

Emma has money into savings accounts. One rate is 8% and the other is 12%. If she has $450 more in the 12% account and the total

AveGali [126]

Let's say that the value invested in the account with a rate of 8% is "x", then the amount invested in the account with a rate of 12% is:

$x+450$

To calculate the total interest we need to calculate the interest of each individual account and sum them:

$\begin{gathered} \frac{8}{100}\cdot x=0.08\cdot x \\ \frac{12}{100}\cdot(x+450)=0.12\cdot x+54 \end{gathered}$

The total interest is the sum of the two expressions above:

$\begin{gathered} 220=(0.08\cdot x)+(0.12\cdot x+54) \\ 220=0.08\cdot x+0.12\cdot x+54 \\ 220-54=0.2\cdot x \\ 166=0.2\cdot x \\ 0.2\cdot x=166 \\ x=\frac{166}{0.2} \\ x=830 \end{gathered}$

The value invested in the account with 8% interest is 830, the one invested in the account with 12% interest is 1280.

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11 months ago

Ella Buys a book and a pen for $14. The cost of the book is two dollars more than twice the cost of the pen. Write a system of l

Vilka [71]

Answer: The book costs $10 and the pen costs $4✔️

Step-by-step explanation:

Let B the cost of the book and let P the cost of the pen.

Then we know:

The book and the pen cost $14:

B + P = $14 } Equation 1

We also know:

The cost of the book is two dollars more than twice the cost of the pen.

B = 2P + $2 } Equation 2

Now we can substitute the value of B from the equation 2 in the equation 1:

2P + $2 + P = $14

3P = $14 - $2 = $12

P = $12/3 = $4 , cost of the pen

Since we know the value of B from the equation 2, we can calculate B:

B = 2P + $2 = 2x$4 + $2 = $8 + $2 = $10 , cost of the book

Answer: The book costs $10 and the pen costs $4✔️

<h3>Verify </h3>

We can substitute these values in equations 1 and 2 and check the results:

B + P = $14 } Equation 1

$10 + $4 = $14 ✔️check!

B = 2P + $2 } Equation 2

$10 = 2x$4 + $2 = $8 + $2 = $10 ✔️check!

<h2>Spymore</h2>

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3 years ago