so width is l-16, l being the length. perimeter is 2w+2l=98. substitute w for l-16 for 2(l-16)+2l=98. Now, distribute to get 2l-32+2l=98. Add 32 to both sides for 2l+2l=130. then, 4l=130. divide both sides by four, so the length is 32.5. plug this into the original perimeter equation for 2w+2(32.5)=98. Again, distribute and subtract so your equation is 2w=33. Divide both sides by 2 so your width is 16.5
so width is 16.5 cm, and length is 32.5 cm
hope this helps!