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2 years ago

7

Notebooks cost $1.20 each. This weekend they will be $.80 What percentage is the sale?

1 answer:

geniusboy [140]2 years ago

6 0

The sale is 33% off notebooks. This can be found by first subtracting .8 from 1.2

1.2-.8=.4 Now divide .4 by 1.2 to get your answer.

$\frac{.4}{1.2}$ =.33

.33=33%

You can also solve this mentally because if you know your basic multiplication tables, 3*4=12 and so $\frac{2}{3}$ of 12 would equal 8.

Does you understand it now?

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George weighs twice as much as his little brother Sam.

german

74 pounds because sam weight 37
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2 years ago

Read 2 more answers

Prove algebraically that r = 10/2+2sinTheta is a parabola

Xelga [282]

Answer:

$y = - \frac{ 1 }{10} {x}^{2} + \frac{5}{2}$

Step-by-step explanation:

We want to prove algebraically that:

$r = \frac{10}{2 + 2 \sin \theta}$

is a parabola.

We use the relations

${r}^{2} = {x}^{2} + {y}^{2}$

and

$y = r \sin \theta$

Before we substitute, let us rewrite the equation to get:

$r(2 + 2 \sin \theta) = 10$

Or

$r(1+ \sin \theta) = 5$

Expand :

$r+ r\sin \theta= 5$

We now substitute to get:

$\sqrt{ {x}^{2} + {y}^{2} } + y = 5$

This means that:

$\sqrt{ {x}^{2} + {y}^{2} }=5 - y$

Square:

${x}^{2} + {y}^{2} =(5 - y)^{2}$

Expand:

${x}^{2} + {y}^{2} =25 - 10y + {y}^{2}$

${x}^{2} =25 - 10y$

${x}^{2} - 25 = - 10y$

$y = - \frac{ {x}^{2} }{10} + \frac{5}{2}$

This is a parabola (0,2.5) and turns upside down.

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2 years ago

I need help before 10:00pm tonight

Citrus2011 [14]

The answer is B. The data is similar throughout the line.

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2 years ago

The vertex of this parabola is at (-2, -3). When the x-value is -1, the

valina [46]

Answer:

-2

Step-by-step explanation:

Start with the vertex form of the equation of a parabola: y - k = a(x - h)^2

Here h = -2, k = -3, x = -1, y = -5. Find a:

-5 - [-3] = a(-1 - [-2])^2, or

-5 + 3 = a(1)^2, or

-2 = a

The unknown coefficient is -2.

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2 years ago

When Maxwell solved his equation, he got 5=5. If he did everything correctly, what does this solution tell him?

hodyreva [135]

Answer: that the solution is true

Step-by-step explanation: if you get something like 10=10 it’s true but if you get like 4= 7 it’s false

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1 year ago