135-3(x-7)=105.............

Question

135-3(x-7)=105.............

Answer 1

135-3(х-7)=105
135-3х+21=105
135+21-105=3х
51=3х
х=51:3
х=17

Answer 2

135-3x+21=105
135+21-105=3x
51=3x
x=17