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3 years ago

What reason completes the proof below given 1/2 x -5 =10 prove x=30

Mathematics

1 answer:

sweet-ann [11.9K]3 years ago

8 0

Answer:

see explanation

Step-by-step explanation:

Given

$\frac{1}{2}$ x - 5 = 10 ( add 5 to both sides )

$\frac{1}{2}$ x = 15 ( multiply both sides by 2 to clear the fraction )

x = 2 × 15 = 30

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Joel made egg sandwiches and tuna sandwiches in the ratio 2:3. He then made 15 more tuna sandwiches and the ratio changed to 1:3

Aleksandr [31]

Answer:

40 sandwiches

Step-by-step explanation:

egg sandwiches : tuna sandwiches

2 : 3

Multiply by x because we do not know how many sandwiches, just the ratio

2x : 3x

Add 15 tuna sandwiches

2x : 3x+15

Now the ratio is 1:3

egg sandwiches : tuna sandwiches

1 : 3

Multiply by y because we do not know how many sandwiches, just the ratio

y : 3y

Set the number of egg sandwiches equal

2x =y

then set the number of tuna sandwiches equal

3x+15 = 3y

We know have a system of 2 equations and 2 unknowns

Substitute y =2x into the second equation

3x+15 = 3(2x)

Distribute

3x+15 = 6x

Subtract 3x from each side

3x-3x+15 = 6x-3x

15 =3x

Divide by 3

15/3 = 3x/3

5 =x

egg sandwiches : tuna sandwiches

2 : 3

Multiply by x because we do not know how many sandwiches, just the ratio

2x : 3x

2*5 3*5

10 15

He originally made 10 egg sandwiches and 15 tuna sandwiches

Then he made 15 more tuna sandwiches

The total number of sandwiches he made is

10+15+15 = 40 sandwiches

5 0

2 years ago

What does the 3 represent in 3(20 15)?

Andre45 [30]

Depending on what you're supposed to do, the three could either mean to distribute it into the equation, giving you
either
(3*2015) or (3*20)*(3*15) or (3*20) +/- (3*15)

Or an example of factoring where they took 3 out of 60 and 45.

There are no instruction on what to do in this question.

4 0

3 years ago

What cubed is equal to 1000?

DerKrebs [107]

Answer:

Step-by-step explanation:

3 0

2 years ago

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Chen completed the division problem below.

jolli1 [7]

Answer:

WHAT? ok ok so

Step-by-step explanation:

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2 years ago

State the value of the discriminant for <br><br>y = <img src="https://tex.z-dn.net/?f=5x%5E2%2B9x-3" id="TexFormula1" title="5x^

Nostrana [21]

Answer:

141, meaning that there will be two real solutions

Step-by-step explanation:

The discriminant of a quadratic is $b^2-4ac$ , which in this case is:

$9^2-4(5)(-3)=81+60=141$

Since the discriminant is positive and not zero, there will be two real solutions to this equation. This is because when the discriminant is negative, and you take the square root of it, you get a negative number. If you take the square root of 0, you get 0, which means that there will only be one solution to the equation.

Hope this helps!

3 0

3 years ago