Vector Algebra: JEE Main 2004 Mathematics question

A particle acted on by constant forces $4\widehat i + \widehat j - 3\widehat k$ and $3\widehat i + \widehat j - \widehat k$ is displaced from the point $\widehat i + 2\widehat j + 3\widehat k$ to the point $\,5\widehat i + 4\widehat j + \widehat k.$ The total work done by the forces is :