Question

subtract the sum of x2−3xy−y2 and 2x2+5xy−4y2 from 6x2−7xy+8y2

Answer 1

Answer:

The Answer is-

${36x}^{2} - 9xy + {13y}^{2}$

Hope it helps!

Answer 2

Answer:

Step-by-step explanation:

The sum of x² - 3xy - y² and 2x² + 5xy - 4y²

x² - 3xy - y² + 2x² + 5xy - 4y²

= (x² + 2x²) + ( - 3xy + 5xy ) + ( -y ² - 4y²) ( ∵ like terms adding )

= 3x² + 2xy + ( - 5y²)

= 3x² + 2xy - 5y² ( ∵ + × - = - )

Now subtract 3x² + 2xy - 5y² from 6x² - 7xy + 8y²

= 6x² - 7xy + 8y² - ( 3x² + 2xy - 5y²)

= 6x² - 7xy + 8y² - 3x² - 2xy + 5y² ( ∵ - × + = - , - × - = + )

= ( 6x² - 3x² ) + ( -7xy - 2xy ) + ( 8y²+ 5y² ) ( ∵ like terms adding )

= 3x² + ( - 9xy ) + 13y² ( ∵ adding : -7 - 2 = - 9 )

= 3x² - 9xy + 13y² is the answer,. ( ∵ + × - = - )