VECTORS 1

If u = 16i + 2j and v = 3i + 10j find 5u - 2v.

solution

= 5u - 3v

= 5(16i + 2j) - 2(3i + 10j)

= 80i + 10j - 6i - 20j

= (80i - 6i) + (10j - 20j)    [grouping like terms]

= 74i - 10j

Hence 5u - 3v = 74i - 10j .

TRY THIS..................

If u = 8i - 3j and v = 5i + 10j;  find 5u + 3v.