Question

9x² - 8xy + 7y² - 4xy - 6x² - 8y² simplify and evaluate for x= -1 and y= -3 ​

Answer 1

The answer is -42

Step-by-step explanation:

Given: Expression 9x² - 8xy + 7y² - 4xy - 6x² - 8y²

To Find: Simplify and evaluate the given expression at x= -1 and y= -3

Solution:

• Simplifying and evaluating the given expression

We have 9x² - 8xy + 7y² - 4xy - 6x² - 8y² which can be simplified as,

⇒ 9x² - 8xy + 7y² - 4xy - 6x² - 8y²

⇒ (9-6)x² + (7-8)y² - 4xy - 8xy

⇒ 3x² - y² - 12xy

And, for x= -1 and y= -3 , we have

​⇒ 3(-1)² - (-3)² - 12(-1)(-3)

⇒ 3 - 9 - 36

⇒ 3 - 45

⇒ -42

Hence, the answer is -42