Robert and Penelope both left their homes at $7pm$ and walked toward a park bench to meet. Robert lives $1650$ feet west of the bench and walks $280$ feet per minute; Penelope lives $1400$ feet east of the bench and walks $300$ feet per minute.

Define a formula to express $d,$ the distance $($in feet$)$ between Robert and Penelope in terms of $t,$ the number of minutes that have passed since $7$:$00$pm$.$ Please show all work!