(18 x b - 1278): 149=36
(18 x b - 1278) = 149 x 36
(18 x b - 1278) = 5364
18 x b =5364 + 1278
18 x b= 6642
b=6642 : 18
b= 369
Si
[(c+ 41 + 56) : 2 - 20] : 10 =3
[(c+ 97) : 2 - 20] : 10 =3
[(c + 97) : 2 - 20] = 10 x3
[(c + 97) : 2 - 20] = 30
c + 97 = (30 + 20) x 2
c + 97 = 100
c= 100 - 97
c= 3
