Factor the difference squares.

Question

a) 64a^2-9

 

b) 81x^4-121

 

 

Answer 1

a) 64a^2-9 = (8a-3)(8a+3)

b) 81x^4-121 = (9x² - 11)(9x² + 11)

 

It will help you immensely if you memorize the squares of all integers from 2 to 25.  Example: 64a² = [8a]²