That was a typo, it should be 3sin(30) which comes to be 1.5 which I had in the 3rd step. Sorry for the typo. Unless I did it wrong anyways? Either way a_y does not effect a_x+b_x which is also off from what the book says.
Find \vec{a}+\vec{b} (Look at the picture)
The book shows the solutions as :
a. 4.1m Along the +x axis.
I however do not know where I went wrong in my calculations.
\vec{a}+\vec{b}=\begin{bmatrix}
a_x+b_x\\
a_y+b_y
\end{bmatrix}=\begin{bmatrix}
|\vec{a}|\cos(30)+|\vec{b}|\cos(45)\\...