VECTORS 4

If u = 16i + 2j and v = 8i + 10j find 5u - 3v

solution

= 5u - 3v

= 5(16i + 2j) - 3(8i + 10j)

= 80i + 10j - 24i - 30j

= (80i - 24i) + (10j - 30j)    [grouping like terms]

= 56i - 20j

Hence 5u - 3v = 56i - 20j .

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

If u = 4i + 3j and v = 17i + 4j;  find 7u - 3v.