Question

Can someone explain/show me how to do this?

Answer 1

v = (-7,-4)

8v would be 8 times both numbers

8v = (8*-7, 8*-4)

8v = (-56, -36)

magnitude = square root( -56^2 + -36^2)
= sqrt(3136 + 1296)
= sqrt(4432 )
= 4 sqrt(277)