Question

out of the following which are not factors of 2x^2 + x - 1​

Answer 1

Answer:

You can look at this as the difference of two squares

[(√2)x]2 = 2x2

Recall the formula (a2-b2) = (a-b)(a+b)

2x2 -1 = (x√2)2 - (1)2

= (x√2 - 1)(x√2 + 1)