Finite Math Examples

$x^{2} - 7 x y + 9 y^{2} + (9 x^{2} - 9 x y - y^{2}) + (- 3 x^{2} + x y - y^{2})$

Step 1

Remove parentheses.

$x^{2} - 7 x y + 9 y^{2} + 9 x^{2} - 9 x y - y^{2} - 3 x^{2} + x y - y^{2}$

Step 2

Add $x^{2}$ and $9 x^{2}$ .

$10 x^{2} - 7 x y + 9 y^{2} - 9 x y - y^{2} - 3 x^{2} + x y - y^{2}$

Step 3

Subtract $3 x^{2}$ from $10 x^{2}$ .

$7 x^{2} - 7 x y + 9 y^{2} - 9 x y - y^{2} + x y - y^{2}$

Step 4

Subtract $9 x y$ from $- 7 x y$ .

$7 x^{2} + 9 y^{2} - 16 x y - y^{2} + x y - y^{2}$

Step 5

Subtract $y^{2}$ from $9 y^{2}$ .

$7 x^{2} + 8 y^{2} - 16 x y + x y - y^{2}$

Step 6

Subtract $y^{2}$ from $8 y^{2}$ .

$7 x^{2} + 7 y^{2} - 16 x y + x y$

Step 7

Add $- 16 x y$ and $x y$ .

$7 x^{2} + 7 y^{2} - 15 x y$