[ ( x + 50 ) . 50 - 50 ] : 50 = 50
[ ( x + 50 ) . 50 - 50 ] = 50 . 50
[ ( x + 50 ) . 50 - 50 ] = 2500
[ ( x + 50 ) . 50 - 50 ] = 2500 + 50
[ ( x + 50 ) . 50 - 50 ] = 2550
x + 50 = 51
x = 51 - 50
x = 1
(x+50).50-50= 50. 50
(x+50).50-50= 2500
(x+50) . 50= 2500+50
x+50= 2550/50
x+50= 51
x= 51-50
x=1