Answer:
21
Step-by-step explanation:
To find the mean, add up all the numbers
15+15+25+29 =84
Divide by the number of numbers
84/4 = 21
Answer: v = -3
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Work Shown:

As you can see, we don't square both sides until the square root portion is fully isolated or on its own side. So it happens after we subtract 1 from both sides.
Technically, you are able to square both sides without first isolating the square root. But that would mean you'd have to use the FOIL rule and things would get a bit messier than they have to be. Not to mention that the square root term wouldn't fully go away (so you'd have to square again later down the line).
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Checking the answer:
Replace every copy of v with -3. Simplify both sides. We should end up with the same number on each side

The answer is confirmed.
Answer:
Angle formed by the sector measuring x% will be 126°.
Step-by-step explanation:
Since, sum of all sectors formed in a circle is 100%.
By adding the measures of all the sectors,
x + x + 21 + 9 = 100
2x + 30 = 100
2x = 70
x = 35%
Now we know sum of all the central angles formed at the center of a circle = 360°
Therefore, angle formed by x% = 360° × 35%
= 
= 126°
Answer:
Point-slope form: y + 3= -1(x + 4)
Slope-intercept form: y = -1x - 7
y = m * x + b,
where:
m is the slope; and
b is the intercept of the y-axis.