The required number is 19 given that -2 is added to a number, the sum is doubled and the result is -15 less than the number. This can be obtained by assuming the number as x, converting the given conditions to algebraic expression, forming algebraic equation and solving for x. 
<h3>Find the required number:</h3>
Here in the question it is given that, 
- The result is -15 less than the number
We have to find the required number. 
Let the required number be x.
⇒ -2 is added to the number ⇒ -2 + x
⇒ the sum is doubled ⇒ 2(-2 + x)
⇒ the result is -15 less than the number ⇒ 2(-2 + x) = x -(-15)
2(-2 + x) = x + 15
⇒ - 4 + 2x = x + 15
⇒ x = 19 
Hence the required number is 19 given that -2 is added to a number, the sum is doubled and the result is -15 less than the number.
Learn more about algebraic expression and equation here:
brainly.com/question/953809
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Answer:
8
24
3
yes
Step-by-step explanation:
the original area of the figure is  4 · 2 which equals 8.
Since the dilation that is needing to be done is by a scale factor of 3 then all we need to do is multiply the original area by 3, which gives us the new area 24.
So because the only transformation was a dilation that didn't significantly change the figure then we can say that both figures are similar.
 
        
             
        
        
        
Step-by-step explanation:
<h2>
<em>So, we call 5 the “square root” of 25 and write √25=5 because 52=25 . ... Since (−5)2 also equals 25 it is also a “square root” of 25 , but we write −√25=−5 because it is not the principal square root. Not all whole numbers have a whole number square root. For instance √2=1.414213562…</em></h2>
 
        
             
        
        
        
Answer:
268.08
Step-by-step explanation:
V=4/3πr² (r=4)
V=4/3π(4)r² = 268.08