Question

subtract -2x² + 5xy + 4y² from the sum of x² - 2xy + y² and 3x² + 4xy - y²

Answer 1

Answer:

6x² - 3xy - 4y²

Step-by-step explanation:

NOTE :

• - * - = +
• + * + = +
• + * - = -
• - * + = -

Add ( sum )

( x² - 2xy + y² ) + ( 3x² + 4xy - y² )

=> x² + 3x² - 2xy + 4xy + y² - y²

=> 4x² + 2xy

Subtract

( 4x² + 2xy ) - ( -2x² + 5xy + 4y² )

=> 4x² + 2xy + 2x² - 5xy - 4y²

=> 4x² + 2x² + 2xy - 5xy - 4y²

=> 6x² - 3xy - 4y²

Answer 2

Answer:

$\sf{6x {}^{2} - 3xy - 4y {}^{2} }$

Step-by-step explanation:

Note :

• - * - = +
• + * + = +
• + * - = -
• - * + = -

Add ( sum )

$\sf{(x {}^{2} - 2xy \: + \: y {}^{2} ) + (3x {}^{2} + 4xy - y {}^{2}) }$

$\sf{ => x {}^{2} - + 3x {}^{2} - 2xy + 4xy + y {}^{2} - y {}^{2} }$

$\sf{ = > 4x {}^{2} + 2xy}$

Substract

$\sf{(4x {}^{2} + 2xy) - ( - 2x {}^{2} +5xy + 4y {}^{2} )}$

$\sf{ = > 4x {}^{2} + 2xy + 2x {}^{2} - 5xy - 4y {}^{2} )}$

$\sf{ = > 4x {}^{2} + 2x {}^{2} + 2xy - 5xy - 4y {}^{2} }$

$\sf{ = > 6x {}^{2} - 3xy - 4y {}^{2} }$