Question

x(t)=-1/3t3+2t2+5t t=5сек

Answer 1

X ( T ) = T * ( - 1\3T^2 + 2T + 5 ) 
X ( 5 ) = 5 * ( - 1\3 * 25 + 15 ) = 5 * ( - 25\3 + 45\3 ) = 5 * (-20\3) = ( -100\3) = 
= ( - 33 1\3)