Answer:
u - v = 17i -13j
Explanation:
Rewrite u=9i-9j and v=-8i 4j vertically:
u=9i-9j
v=-8i + 4j
We want to subtract the second equation from the first:
u=9i-9j
v=-8i + 4j
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u - v = 17i -13j
Note: I assumed that a " + " sign precedes 4j in the second equation.