The depth of the submarine, DDD, in feet below sea level, after ttt minutes have elapsed is given by the function D(t)=20+16tD(t)=20+16tD, left parenthesis, t, right parenthesis, equals, 20, plus, 16, t.

The pressure, PPP, in pounds per square inch, exerted on the submarine at a depth of xxx feet is given by the function P(x)=14.7+0.445xP(x)=14.7+0.445xP, left parenthesis, x, right parenthesis, equals, 14, point, 7, plus, 0, point, 445, x.

Find an explicit expression that models the pressure exerted on the submarine as a function of the elapsed time, ttt, in minutes.