Difference of Squares

x² - 9

• (x + 3) (x - 3)

• (x - 3) (x - 3)

• (x + 3) (x - 6)

• Can't factor using Diff. of Squares

4a² - 25

• (2a + 5) (2a - 5)

• (2a - 5) (2a - 5)

• (x + 5) (x - 5)

• Can't factor using Diff. of Squares

q² - 121

• (q + 11) (q - 11)

• (q - 11) (q - 11)

• (q + 11) (q + 11)

• Can't factor using Diff. of Squares

r² - 9t²

• (r + 3t) (r - 3t)

• (r - 3t) (r - 3t)

• (3r + t) (3r - t)

• Can't factor using Diff. of Squares

x² - 9

• (x + 3)²

• (x + 3) (x - 3)

• (x - 3)²

• x + 3(x - 3)

Fully Factor the Following
25x²-81

• (5x-9)²

• (5x+9)(5x-9)

• 25(x-9)²

• (9x+5)(9x-5)

Which of these can factor using difference of two squares?

• 144x² - 49y²

• x² + 4x - 12

• 100x² + 20x + 1

• 14x - 16

Which one is false about the difference of two squares?

• We can factor because there is addition sign.

• We can factor because there is a perfect squared number (Example: x², 25, 49)

• Formula: a² - b² = (a + b) (a - b)

• We can factor because there is minus sign.

We can't factor using difference of two square this 49x² + 4y². Why?

• Because 4 is not a perfect cubed number.

• Because 4 is not a perfect squared number.

• Because 49 is not a perfect squared number.

• Because we can't factor using difference of two squares if it is addition sign.

x² - 400

• ( x - 200) ( x + 200) 

• ( x + 20) ( x + 20) 

• Prime

• ( x - 20) ( x + 20)