SAT Math Practice Question #8

This video looks at a SAT Math practice question

[@p1erz548]

Fantastic problem and video, thanks for showcasing

[@anonymouscheesepie3768]

(x^2 - 1)/(x - 1) = -2 x^2 - 1 = -2x + 2 x^2 + 2x - 3 = 0 (x - 1)(x + 3) = 0 x = 1 and -3 however, checking for extraneous solutions, we see that x = 1 could not work because it creates a 0 in the denominator. we can also see this by simply canceling the (x - 1) in the original equation since x^2 - 1 is expressible as (x + 1)(x - 1), showing that at x = 1, there is a hole in the equation, thus proving that it is an extraneous solution. thus, the only answer is x = -3.