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3 years ago

I think of a number double it add 15 my number is 21 what number was i thinking about

Mathematics

1 answer:

AleksandrR [38]3 years ago

5 0

Hello from MrBillDoesMath!

Answer:

Discussion:

Let the number be "n",

2n + 15 = 21 => subtract 15 from both sides

2n = 21 - 15 = 6 => divide both sides by 2

n = 6/2 = 3

Check: Start with 3. Double it (gives 6), add 15 to it ( 6 + 15) which gives 21/

Thank you,

MrB

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iris [78.8K]

Answer:

Step-by-step explanation:

To find the determinant of a 3x3 matrix, you can use this method. (See picture.)

Start with the first number in the top row, and block off the row and column. A 2x2 matrix will be left. Find the determinant of this 2x2 matrix, and multiply it by the number in the top row.

Repeat for the other two numbers in the top row. Add the first result, subtract the second, and add the third.

det A = -2 [(3)(-5) − (a)(0)] − 2 [(0)(-5) − (a)(0)] + b [(0)(0) − (3)(0)]

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2 years ago

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Answer:

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3 years ago

One endpoint of a line segment is (–6, 4), and the midpoint of the segment is (–2, 7). What are the coordinates of the other end

Arturiano [62]

Answer:

A. (2, 10)

Step-by-step explanation:

If there are two points (x1,y1) and (x2,y2) on a coordinates plane then

coordinates of the midpoint is given by (x1+x2)/2, (y1+y2)/2

__________________________________________________

Given

one endpoint is (–6, 4) and midpoint is (–2, 7)

let coordinates of other endpoint be (x,y)

now if one endpoint is (–6, 4) and other endpoint is (x,y)

then coordinates of midpoint is ((-6+x)/2 , (4+y)/2)

while the coordinates of midpoint given is (–2, 7)

thus (–2, 7) should be equal to ((-6+x)/2 , (4+y)/2)

-2 = (-6+x)/2 and 7 = (4+y)/2

=> -2*2 = -6+x => 7*2 = 4+y

=> -4 = -6+x => 14 = 4+y

=> -4+6 = x => 14-4 = y

=> x = 2 => 10 = y

Thus, coordinates of the other endpoint is(2,10)

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3 years ago

Pls asap now<br> late thank you

allsm [11]

Answer:

using Pythagoras theorem

Step-by-step explanation:

it's option c

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2 years ago

Read 2 more answers

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diamong [38]

This is what I learned:

D = Divide
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D= Dad
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Hope this helped you! :)

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3 years ago