Step-by-step explanation:
step 1. an example of difference of squares (dos) is (x + y)(x - y) = x^2 - y^2.
step 2. dos must have only 2 square rootable terms and a "-" between them.
step 3. 196x^2 - 121y^2 = (14x + 11y)(14x - 11y) works!
step 4. 5x^2 - 245 = 5(x^2 - 49) = 5(x + 7)(x - 7) works!
step 5. 27w^5 - 75w = 3w(9w^4 - 25) = 3w(3w^2 + 5)(3w^2 - 5) works!
step 6. x^4 - 100y^2 = (x^2 - 10y)(x^2 + 10y) works!
