Question

30 + 25 - 16 = [ (? x 2) : 4] - 1

Answer 1

30 + 25 - 16 = [ (? x 2) : 4] - 1
39= [(? x 2) : 4 ] -1
39 + 1 = (? x 2) :4
40 . 4 = ? x 2
160/2 = ?

80= ?