Hi i'd be glad to help you with this equation. 
basically all we have to do is find (65%) of 455*. 
65% of 455* = 295.75 
Next. 
455 + 295.75 = 750.75 
So, to check my work I have 750.75 miles in total. 
I have already driven 455 miles of 750.75 miles. 
Using subtraction we subtract our distance from our total. 
750.75 - 455 = 295.75 
So, in total your answer to this problem is (295.75) 
Hope this helps. 
Have a great day!