Question

Subtract the sum of 7x2 - 4y2 and 4x² + 3xy - 4y? from the sum of 5x² - 3xy - y and x2 + 2xy - 2y?​

Answer 1

Answer:

$4 {y}^{2} - 5 {x}^{2} - 4xy + y$

Step-by-step explanation:

(1)

$(7 {x}^{2} - 4 {y}^{2} ) + (4 {x}^{2} + 3xy - 4y) \\ = 11 {x }^{2} - 4 {y}^{2} + 3xy - 4y$

(2)

$(5 {x}^{2} - 3xy - y) + ({x}^{2} + 2xy - 2y) \\ = 6 {x}^{2} - xy - 3y$

Now subtracting (1) from (2).

$(6 {x}^{2} - xy - 3y) - (11 {x}^{2} - 4 {y}^{2} + 3xy - 4y) \\ = - 5 {x}^{2} + 4 {y}^{2} - 4xy + y \\ = 4 {y}^{2} - 5 {x}^{2} - 4xy + y$