1. 401 + 18*x*z, for z = 10

we plug in z = 10,

401 + 18*x*10

401 + 180x

2. 55 - K/6 for k = 30

we plug in k = 30,

55 - 30/6

55 - 5

50

3. 32 + 55 x b/11 for b = 2

let us see you try to do 3 by substituting b=2, I'll correct you if you make a mistake.