Resposta :
a)
(x-6)!=120
120=1.2.3.4.5
120=5!
(x-6)!=5!
x-6=5
x=5+6
x=11
b)
6!=6.5.4.3.2.1=720 maneiras
(x-6)!=120
120=1.2.3.4.5
120=5!
(x-6)!=5!
x-6=5
x=5+6
x=11
b)
6!=6.5.4.3.2.1=720 maneiras