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4 years ago

The sum of twice a number and 18 less than the number is the same as the difference between -30 and the number

Mathematics

2 answers:

maksim [4K]4 years ago

6 0

2x + x - 18 = -30 - x

Monica [59]4 years ago

6 0

Lets say the number is x. The formula would be:
2x + x - 18 = x -30
To find x, you have to get rid of everything els, so minus x from both sides.
2x - 18 = -30
Since -30 is the smallest number, you get rid of that next. Add 30 to both sides
2x + 12 = 0
Now get rid of +12 by doing -12.
2x = -12
divide both sides by 2 to get x by itself
x = -6.

To double check your answer, do the reverse. Substitute -6 iinto the equation wherever it says x.

2x + x - 18 = x -30 becomes (2 x -6) + (-6 - 18) = -6 - 30.
Use BIDMAS (Brackets Indices Division Multiplication Addition Subtraction) to get your answer. Brackets are first
-12 + -24 = -6 - 30
-36 = -6 - 30 which is basically -36 = -36

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3 years ago

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The measure of b is ____.

Vedmedyk [2.9K]

Answer:

$\Huge\boxed{b=21}$

Step-by-step explanation:

Pythagorean Theorem:

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3 years ago

ABCD is a parallelogram. Determine the length of AD.

ale4655 [162]

Answer:

D) 10 units

Step-by-step explanation:

Opposite sides of a parallelogram are congruent.

<h3>setup</h3>

The relation between opposite sides tells you ...

BC = AD

2x = x +5

<h3>solution</h3>

x = 5 . . . . . . . subtract x from both sides of the equation

We want the length of AD, which is ...

AD = x +5 = 5 +5

AD = 10

_____

<em>Additional comment</em>

Often, it seems like the question is answered once the value of x is found. Here, finding the value of x is an <em>intermediate step</em>. The value of x is needed in order to be able to answer the question about <em>the value of an expression involving x</em>.

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