Error in last line of linear algebra exercise

[mathijs-creemers-uh]

It says Recalling that y = xtu, we can conclude that y = xtuu.

but it should be

recalling that y = alpha.u (and knowing that aplha = xtu) we can conclude that y = xtuu

[yeefan]

In the same exercise:
The question never said that u is a unit vector, but the solution "used the fact that u is a unit vector".