Упрости выражения:
4b+(r-b)*2;
(4+12)*a+7*c
(6+5+8)*c-9*a
17*b - 4*b+8*c
56*d+(6+7)*d
5*(a+b+c)+2*b
(d+c)*5+4*d
(d+c)*4- 2*d
62*c - 34*c+6*c

4b+(r-b)*2=4b+2r+2b=6b+2r;

(4+12)*a+7*c=4a+12a+7c=16a+7c;

(6+5+8)*c-9*a=6c+5c+8c-9a=19c-9a;

17*b-4*b+8*c=17b-4b+8c=13b+8c;

56*d+(6+7)*d=56d+6d+7c=69d;

5*(a+b+c)+2*b=5a+5b+5c+2b=5a+7b+5c;

(d+c)*5+4*d=5d+5c+4d=9d+5c;

(d+c)*4-2*d=4d+4c-2d=2d+4c;

62*c-34*c+6*c=62c-34c+6c=34c;