Do the indicated calculation for the vectors u = (5,-2) and w=(-1,-5). u.W u.w= (Simplify your answer. Type an integer or a fraction.) Calculate 4u - 5v. u= 6, -2) and v= {-4, 7) 4u – 5y= Find the magnitude of vector v if v = (-5,8). The magnitude of v is (Simplify your answer. Type an exact answer, using radicals as needed.)