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3 years ago

Solving systems by elimination with multiplication: 8x+7y=20 and 4x-4y=-20

1 answer:

3 0

If you put 0 in the place of x or y, which every one you choose, it will cancel it or and you can just divide the number next to it by the answer (-20, 20). Take it one step at a time, don't try to do both at the same time.

You might be interested in

What is 10% as a decimal?

DiKsa [7]

Hi there!

10% as a decimal is 0.1

To find the decimal of a percentage, just divide the percentage by 100.

10/100 = 1/10 = 0.1

I hope this helps!

6 0

3 years ago

The dimensions of a gymnastic floor are 40 ft by 40 ft. the performance floor is 1 ft less, or 39 ft, per side.

Mashutka [201]

Answer:

the square root of 3200

Step-by-step explanation:

I'm not sure if this is right, because the format of the question wasn't clear, but it sounded like we have to find the diagonal distance of the room from one corner to the opposite. If the sides are 40ft long on both sides, we can use the Pythagorean Theorem to solve this:

40^2+40^2=c^2

1600+1600=c^2

3200=c^2

c=sqrt(3200)

or about 56.5

4 0

2 years ago

to arrive at 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution. How many liters of eac

CaHeK987 [17]

Answer:

800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.

Step-by-step explanation:

Given:

At 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution.

Now, to find the number of liters of saline solution each should be used.

Let the liters of 90% saline solution mix be $x.$

And let the liters of 40% saline solution mix be $y.$

So, the total number of liters:

$x+y=2000.$

$y=2000-x\ \ \ ....(1)$

Now, the total percentage of saline solution:

$90\%\ of\ x+40\%\ of\ y=60\%\ of\ 2000$

$\frac{90}{100}\times x+\frac{40}{100}\times y=\frac{60}{100}\times 2000$

$0.9x+0.4y=1200$

Substituting the value of $y$ from equation (1) we get:

$0.9x+0.4(2000-x)=1200$

$0.9x+800-0.4x=1200$

$0.5x+800=1200$

Subtracting both sides by 800 we get:

$0.5x=400$

Dividing both sides by 0.5 we get:

$x=800.$

The liters of 90% saline solution mix = 800.

Now, substituting the value of $x$ in equation (1) to get the liters of 40% saline solution:

$y=2000-x$

$y=2000-800$

$y=1200.$

Thus, the liters of 40% saline solution = 1200.

Therefore, 800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.

8 0

3 years ago

What is 2/5 as a decimal

disa [49]

2divided 5 =0.4
if 2 is over the 5 you divide the 2 by 5 to get the decimal and then you get 0.4/

5 0

3 years ago

Read 2 more answers

The Ericsson method is one of several methods claimed to increase the likelihood of a baby girl. In a clinical trial, results co

Travka [436]

Answer:

0.001

Step-by-step explanation:

Ericsson is claimed to increase the likelihood of a baby girl ;

Given the alternative hypothesis to buttress this claim :

HA : p>0.5

In other to establish the success of Ericsson's claim, then there must be significant evidence to reject the Null hypothesis ; hence adopt the alternative.

To Do this, we need a very small Pvalue ; such that it will be lesser than the α - value in other to reject the Null and adopt the alternative.

Recall ;

Pvalue < α ; We reject the Null

Therefore, from the options, we choose the smallest Pvalue as we want the Pvalue to be as small as possible.

4 0

3 years ago