Question

Which of the expressions below could be factored quickly using the "difference of squares"? Select all that apply.

Answer 1

Answer:

• 81x² - 12, no as 12 is not a perfect square
• x^2 + 25, no as it is a sum of squares
• 4x^2 - 25, yes
• 9x^2 - 16, yes
• x^2 - 50, no as 50 is not a perfect square
• x^2 - 81, yes
• x^2 - 100, yes

Answer 2

Answer:

Difference of squares method is a method that is used to evaluate the difference between two perfect squares.

For example, given an algebraic expression in the form:

can be factored as follows:

From the given expressions, the only expression containing two perfect squares with the minus sign in the middle is the expression in option A.

i.e.  

which can be factored as follows:

.