3*7^х+1 + 5*7^х-1=152

Question

3*7^х+1 + 5*7^х-1=152

Answer 1

7 ^ X * ( 3 * 7 + 5 * ( 1/7 ) ) = 152 
7 ^ X = 152 : ( 21 + (5/7 ))
7 ^ X = 152 : ( 152/7 ) 
7^X = 7 
X = 1