Add (-4y^2 + 2xy - 6x^2) plus (5y^2 - 6xy + 7y^2)?

Question 1
8 y ² - 4 x y - 6 x ²

Question 2
9 x y + 3 x + 4

Add like terms

= -4y² + 5y² + 7y² + 2xy - 6xy - 6x²
= 8y² - 4xy - 6x²

I think the second bracket last term was supposed to be 7x², not 7y². In that case, the answer would be:

= -4y² + 5y² + 2xy - 6xy - 6x² + 7x²
= y² - 4xy + x²

2)

=3xy + 6xy - 2x + 5x + 7 - 3
=9xy + 3x + 4

(-4y^2 + 2xy - 6x^2) + (5y^2 - 6xy + 7y^2)
= -4y^2 +5y^2+ 7y^2 + 2xy - 6xy - 6x^2 rearrange
= 8y^2 -4xy -6x^2 combine like-terms




(3xy - 2x + 7) + (6xy + 5x - 3)
=9xy + 3x +4

Combine like terms.

Q 1
Are you sure type right? I assume it is (5y^2 - 6xy + 7x^2)

y ² - 4 x y + x ²

Q 2
9 x y + 3 x + 4

3y^2 -4xy-x^2
9xy+3x+4.

9xy + 3x + 4