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3 years ago

Find the number to add to x^2-18x

Mathematics

1 answer:

pentagon [3]3 years ago

4 0

Answer:

A. add 81; $(x-9)^2$

Step-by-step explanation:

The perfect square formula

$(a-b)^2=a^2-2ab+b^2$

Rewrite expression $x^2-18x$ as follows:

$x^2-2\cdot 9\cdot x$

So, to form a perfect square, $+9^2$ is missed.

When we add $9^2=81,$ we will get

$x^2-2\cdot 9\cdot x+9^2=(x-9)^2$

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Semenov [28]

Answer:

median

Step-by-step explanation:

the median would make the score as good as possible, because there could be possible outliers. this really depends on if there are outliers or not. here is an example of what i need:

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3 years ago

375 of the students at Haldane Elementary School walk to school. If these

ELEN [110]

Answer:

506

Step-by-step explanation:

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2 years ago

What is the cosine ratio for ∠F? p.s. show how you got your answer!

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6/10 its adjacent over hypotenuse

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2 years ago

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A traffic helicopter descends 153 meters to be 445 meters above the ground, as illustrated in the

sertanlavr [38]

Answer:

598 meters

Step-by-step explanation:

In the problem, the word 'decend' means to decrease in elevation.

Our equation:

$? - 153 = 445$

Add 153 to both sides of the equation:

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598 meters represents the original height of the helicopter.

6 0

1 year ago

Calvin is painting an area that is 115 square feet. He is able to paint 2.5 square feet every 2 minutes. At this rate , how long

Verdich [7]

Answer:

Calvin will paint the entire area in 92 minutes or 1 hour 32 minutes.

Step-by-step explanation:

First of all we know that the total surface are that Calvin is painting is 115 square feet.

The rate at which Calvin is painting refers to the surface area he covers every 2 minutes. This is 2.5 square feet every 2 minutes.

we can set up a relation to solve this problem

If Calvin paints $2.5 ft^{2}$ in 2 minutes

He will paint $115 ft^{2}$ in $x$ minutes

By cross multiplying, we have $x= \frac{2 \times 115}{2.5}=92 minutes$

Hence Calvin will paint the entire area in 92 minutes or 1 hour 32 minutes.

3 0

2 years ago