The answer to your question is 20
Answer:
Step-by-step explanation:
Given
See attachment
Required
The probability that a 7th grader selected will play guitar.
From the attachment, we have:
7th graders that can play guitars are:
So, the probability is:
Y = |x - 21| represents an absolute value function.
The polynomial to be added to –7mn + 2m² + 3n² to obtain 5m² + 2mn - 9n² is: 3m² - 11n² + 9mn.
<h3>Addition of Polynomials</h3>
Like terms should be combined together when adding polynomials.
Let x represent the polynomial expression that would be added to –7mn + 2m² + 3n² to obtain 5m² + 2mn - 9n².
Therefore:
–7mn + 2m² + 3n² + x = 5m² + 2mn - 9n².
x = 5m² + 2mn - 9n² - (-7mn + 2m² + 3n²)
x = 5m² + 2mn - 9n² + 7mn - 2m² - 3n²
Combine like terms together.
x = 3m² - 11n² + 9mn
Therefore, the polynomial to be added to –7mn + 2m² + 3n² to obtain 5m² + 2mn - 9n² is: 3m² - 11n² + 9mn.
Learn more about polynomial on:
brainly.com/question/24662212
