An object of mass $4kg$ is moving along $X-$axis such that its position $x$ varies with time $t$ as $x^2=16t^3$, with $x$ in meter and $t$ in sec. work done as a friction of time can be shown as:

The position function X(t) of a particle moving along an $X$ axis is $X$
= 4.0 - 6.0${}_t$ ${}^2$, with $X$ in meters and $t$ in seconds. Graph $X$ versus $t$ for the range -5 s to +5 s. To shift the curve rightward on the graph, should we include the term +20$t$ or the term -20$t$ in $X(t)$?