(8b-3)(3b+8)-3b(8b+3) при b=9,4

Question

(8b-3)(3b+8)-3b(8b+3) при b=9,4

Answer 1

24b+64-9b-24-24b-9b
= -18b+40
-18*9,4+40=-169,2+40=-129,2

Answer 2

(8*9,4)*(3*9,4+8)-3*9,4*(8*9,4+3) будет 
75,2*36,2-28,2*78,2= 2722,24-2205,24=517