Wheel offset Q

[snail power]

Just looking at a set of wheels I kow can fit pattern wise but have an offset of 35mm... Would I need to throw in a 1/2" spacer to compensate somewhat for the higher offset or if I am mistaken....please correct me or provide the info I seek.
btw size of wheels are 18x8 F 18x9.5 R

thanks,

Nick