To solve this, follow these steps:
5x + 27 = 9 (x+3) - 4x
Distribute the 9 within the parenthesis:
5x + 27 = 9x + 27 - 4x
Then combine like terms:
5x + 27 = 5x + 27
These two then cancel each other out completely.
This is an identity because an identity in math is when both equations equal each other, which is shown above.
Hope this helps!
<span>Two cars start moving from the same point. one travels south at 48 mi/h and the other travels west at 20 mi/h. at what rate is the distance between the cars increasing four hours later? so its 400%</span>
Solution
Problem 6
For this case we can do this:
12, 16,__, 14, 8, 7
We can solve for x like this:
Problem 7
F
The sample size should be 250.
Our margin of error is 4%, or 0.04. We use the formula
To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide both sides by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value has a z-score of approximately 2.33. Using this, our margin of error and our proportion, we have:
Divide both sides by 2.33:
Square both sides:
Multiply both sides by n:
Divide both sides to isolate n: