two space ships approach the earth from opposite directions

two space ships approach the earth from opposite directions. according to an observer on earth space ship a moves at .753c and ship b at a speed of .851c. what is the speed of a observed from b and speed of b observed from a?

(modern physics)

Speed of \'a\' observed from \'b\' = Speed of \'b\' observed from \'a\' = (0.851+0.754)c = 1.605c