Mark M. answered 08/03/21
Retired math prof. Calc 1, 2 and AP Calculus tutoring experience.
To find a unit vector that is in the same direction as a given vector, multiply the given vector by 1 over its magnitude.
So, for the vector -5i + 7j, the magnitude is √[(-5)2+72] = √74
Unit vector: (-5/√74) i + (7/√74) j
Do the other problem in a similar manner.