Elizabeth simplified (x – 2)2 to x2 – 4. Did she multiply correctly? If not, explain her error(s) and show the correct work with the correct answer.
No...she made the common error of distributing the exponent over both terms in the parentheses.....this is incorrect......it should be.....
(x - 2)^2 =
(x - 2) (x - 2) =
x^2 - 2x - 2x +4 =
x^2 - 4x + 4
If you mean 2(x-2) then yes, Elizabeth is correct. as it would be 2x-4.
If you mean (x-2)2 then no, CPhill is correct. :)
