Multiple choice test

Pulling common factors out

For any of the following questions there is exactly one correct answer. You may click at any of the question marks to uncover whether the corresponding answer is the true or false. Take a sheet of paper whenever you feel this might help, in particular for the questions indicated by the symbol at the right. You may also print this page and use it as worksheet. At the end of the document, you may activate an evaluation in terms of number of points achieved.

 4 c2 + 12 x   =
 4 (c2 + 3 x) 4 (c2 + 12 x) 4 c2 (1 + 12 x)
 2 a b - a2   =
 a2 (2 b - 1) a (2 b - a) b (2 a - a2)

 3 x2 - 9 x y   =
 9 x2 y (3 y - x) 3 x2 (1 - 3 y) 3 x (x - 3 y)
 A2 + 16 (y + 2) A   =
 A2 (1 + 16(y + 2) ) A (A + 16 y + 32) 16 (A2 + (y + 2) A)

 9 (a2 - 1) - 3 (b2 - 3)   =
 3 (3 a2 - b2) 3 (3 a2 - b2 + 2) 3 (3 a2 - b2 + 6)
 9 (a2 - 1) + 3 (b2 - 3)   =
 3 (3 a2 + b2) 3 (3 a2 + b2 - 3) 3 (3 a2 + b2 - 6)

 1 + x + x2   =
 x (1 + x) 1 + x (1 + x) 1 + x (1 + 2 x)
 3 (b - 1) + (b - 1)2   =
 (b - 1) (b + 2) 4 (b - 1) 3 (b - 1) (1 + (b - 1)2 )

You have achieved    out of 16 possible points.
Information on the evaluation system