An easy question that I can't seem to do.
Show that (2√2+2)² = 12+8√2
The method I have been taught is the grid method (diagram below is meant to be a grid I can't seem to draw it so use your imagination :P ):
......2√2.......2
2√2..X.......4√2
.
2.....4√2......4
But I can't do 2√2 x 2√2. Some help? I can work its meant to be 8 so I can do the question but how would I do that?