1/2 X base X height= triangle
length X width X height= square
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:
23d + 45 = 137
Explanation:
Since it is $23 per day, that dollar amount must be associated with a variable that multiples it per day that it is rented. Finally, you need to add the one time $45. This equation can then be used to find how many days it was rented for.
23d + 45 = 137
23d = 92 (Subtract 45 from both sides)
d = 4 (Divide by 23 on both sides)
The rug-cleaning machine was rented for 4 days. You found this using the equation: 23d + 45 = 137
$91 because 10% of 70 is $7 and 20% of 70 is $14 so 7+14+70= $91