Idon’t get any of this can someone explain what to do and how i can get my

Its just a matter of subbing ur numbers into the formula given
1. d = rt
    when r = 144 and t = 18
    now we sub
    d = 144 * 18
    d = 2592 <==
2. d = rt
    when r = 56 and t = 3.5
    sub
    d = 56 * 3.5
   d = 196 <==

3. A = L * W
    when L = 2 ft and W = 15 inchesthis one u have to convert to     inches...2 ft = 24 inches...so L = 24 and W = 15
    A = 24 * 15
    A = 360 in^2 <==

4. A = L * W
    L = 3m and W = 32 cm...have to convert to cm1 m = 100 cm...so 3 m = 300 cm
    A = 300 * 32
    A = 9600 cm^2 <==

u basically do the same for all the othersits just a matter of subbing and solving