Question

A. (x-1)!=720
B.(5x-20)!=120

Answer 1

a) (x-1)! = 10!
x-1=10
x= 10+1
x=11

b) (5x-20)! =5!
5x-20= 5
5x=5+20
5x= 25
x=25/5
x=5