Question

A=4i+5j-6k , b=2i-3j+4k so (a+b) * (a-b)

Answer 1

didn't understand the question

Answer 2

Answer:

48

Explanation:

a+b = (4i+5j-6k ) + (2i-3j+4k)

      = (4i +2i) (5j +(-3j)) (-6k +4k)

      = (6 i +2j-2k )

a-b =(4i+5j-6k ) - (2i-3j+4k)

     =(4i -2i) (5j -(-3j) (-6k -4k)

     =(2i+8j-10k)

(a+b) * (a-b) = (6 i +2j-2k ) . (2i+8j-10k)

                   = ax bx + ay by + az bz

                   = 6 *2 + 2 * 8 +( -2 * -10)

                   = 12 + 16 + 20

                   = 48