Factoring and Difference of Squares

Which of these can ONLY BE factored using difference of two squares?

• 144x² - 49y²

• x² + 4x - 12

• 100x² + 20x + 1

• 14x - 16

• 1(x - 5)

• x(x - 5x)

• x(x - 5)

• x²(1 - 5)

Factor using GCF: 3x^3+9x^2-15x

• x(3x² + 9x - 15)

• 3x(x² + 3x - 5)

• 3x(x² - 9x + 15)

• x(3x² -9x + 15)

4x² - 25

• (2x + 5) (2x - 5)

• (2x - 5)²

• (2x + 5)²

• 2x + 5(2x - 5)

• 2x²(80x³-70-60x⁶)

• 10x²(80x⁴-70x-60x⁶)

• 10x²(8x³-7-6x⁵)

• 3x²(80x³-40-60x⁵)

• Yes, because the teacher is always right!

• No, because 9 doesn't divide into 18 and 36. There are too many variables.

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.

What factoring method should I use?

• GCF

• Grouping

• Difference of Squares

• Trial and Error