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Varvara68 [4.7K]
3 years ago
5

What are the solutions to the equation x2 − 1 = 399?

Mathematics
2 answers:
Mila [183]3 years ago
8 0

Answer:A

Step-by-step explanation:

mihalych1998 [28]3 years ago
3 0

Good evening ,

Answer :

A.

x = ±20

Step-by-step explanation:

x² − 1 = 399 ⇔ x²= 400 ⇌ x² = 20² ⇌ x² − 20² = 0 ⇌ (x-20)(x+20) = 0

⇌ x = 20 or x = -20.

:)

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Megan has read 45% of her 382 page novel. how many pages has she read?
KiRa [710]

Answer:

171.9 pages

Step-by-step explanation:

45%         x

------   =  -------

100        382

45 x 382 = 17190      100 · x = 100x

17190 ÷ 100x = 171.9 = x

7 0
3 years ago
The width of the rectangle
Nikolay [14]

Answer:

84cm^2

Step-by-step explanation:

P=2l+2w

We are given,

P=40cm

l=2w+2

Plug these into the first formula and solve for the dimensions,

length and width, of the rectangle:

40=2(2w+2)+2w              Simplify

40=4w+4+2w

40=6w+4

36=6w

6=w OR the width is 6cm, therefore,

the length is

l=2(6)+2

l=14cm

To calculate the area of a rectangle, A=lw,

plug the length,14cm, and the width, 6cm, into this formula

A=(14)(6)

A=84cm2 OR the area of the rectangle is 84cm^2

7 0
3 years ago
Plz help first to answer gets 50 points
djverab [1.8K]
D is the correct answer bc the 3’s continue forever
5 0
3 years ago
Read 2 more answers
A patient is using Humulin insulin U-100. The patient is to use 35 units three
Pani-rosa [81]
A is the correct answer. Please give me brainliest
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4 years ago
Which choice is equivalent to the expression below when y2 0?<br> √y^2 + √16y^3 – 4y√y
DanielleElmas [232]

Answer:

Option C.

Step-by-step explanation:

We start with the expression:

\sqrt{y^3}  + \sqrt{16*y^3} - 4*y\sqrt{y}

where y > 0. (this allow us to have y inside a square root, so we don't mess with complex numbers)

We want to find the equivalent expression to this one.

Here, we can do the next two simplifications:

\sqrt{16*y^3} = \sqrt{16} \sqrt{y^3} = 4*\sqrt{y^3}

And:

y*\sqrt{y} = \sqrt{y^2} *\sqrt{y} = \sqrt{y^2*y} = \sqrt{y^3}

If we apply these two to our initial expression, we can rewrite it as:

\sqrt{y^3}  + \sqrt{16*y^3} - 4*y\sqrt{y}

\sqrt{y^3}  + 4*\sqrt{y^3} - 4\sqrt{y^3} = \sqrt{y^3}

Here we can use the second simplification again, to rewrite:

\sqrt{y^3} = y*\sqrt{y}

So, concluding, we have:

\sqrt{y^3}  + \sqrt{16*y^3} - 4*y\sqrt{y} = y*\sqrt{y}

Then the correct option is C.

8 0
3 years ago
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