VECTORS 1

If u = 6i + 2j and v = 7i + 10j find 5u - 3v

solution

= 5u - 3v

= 5(6i + 2j) - 3(7i + 10j)

= 30i + 10j - 21i - 30j

= (30i + 21i) + (10j - 30j)

= 51i - 20j

Hence 5u - 3v = 51i - 20j

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

If u = 7i + 3j and v = 4i + 4j;  find 2u + 6v.