Question

If u = 2i - j; v= -5i + 4j and w = j find 4u (v -w).

Answer 1

To find 4u (v -w)

First replace the terms

u = 2i - j; v= -5i + 4j and w = j

4u (v -w)

4(2i-j) ((-5i + 4j)-( j ))

4(2i-j) ((-5i + 4j- j ))

4(2i-j) ((-5i + 3j ))

8i - 4j((-5i + 3j ))

-40i² + 24ij +20ij -12j²

-40i² +44ij -12j²