VECTORS 2

If u = 20i + 2j and v = 3i + 10j find 5u + 3v

solution

= 5u + 3v

= 5(20i + 2j) + 3(3i + 10j)

= 100i + 10j + 9i + 30j

= (100i + 9i) + (10j + 30j)

= 109i + 40j

Hence 5u + 3v = 109i + 40j .

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

NECTA 2001 QN. 12a (i)

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