The dimensions of the base of Box 1 are x by 3x.The dimensions of the basex by 4x - 1.The base area of Box 1 is.0 4x² - x3xO4x² - 13.x24x - 43x?o .5x - 14xDONECOMPLETE

The area of the base is given by the multiplication of its dimensions, then we have:
[tex]x\left(4x-1\right)=4x^2-x[/tex]Therefore, the area of the base is:
[tex]\begin{equation*} 4x^2-x \end{equation*}[/tex]