`u = 4i - j, v = i - j` Find `u*v`.

You need to evaluate the product of the vectors `u = u_x*i + u_y*j, v = v_x*i + v_y*j,` such that:

`u*v = u_x*v_x + u_y*v_y`

`u*v = (4)*(1) + (-1)*(-1)`

`u*v = 4 + 1`

`u*v = 5`

Hence, evaluating the product of the vectors` u = u_x*i + u_y*j, v = v_x*i + v_y*j,u = <4,-1>, v = <1,-1>,` yields `u*v = 5.`