17x(1-2y)
17x-34xy
because both expressions have a x, it would be easier to factor out the x first. but because 17 is a factor of 34 you can simply divide 34 by 17 and get 2. so you put it together to this,
17x(1-2y)
Because, 17x times 1 is 17x but 17x times -2y would be -32xy.