Answer:
18.91
Step-by-step explanation:
18.91
The one is in the cents place, so we cannot round because there are no more digits
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
Answer:
x=-7
Step-by-step explanation:
-(x-13)=10(x+9)
distribute the negative on the left side and the 10 on the right side
-x+13=10x+90
add x on both sides
13=11x+90
subtract 90 on both sides
-77=11x
divide 11 on both sides
-7=x
x=-7
