SOLUTION: Let u= <5,-3> and v=<-2,9> be vectors. Find this indicated expression: 2v x u Apparently, the answer is -74 but I keep getting some other weird answer.. Thanks if you can h

Algebra ->  Trigonometry-basics -> SOLUTION: Let u= <5,-3> and v=<-2,9> be vectors. Find this indicated expression: 2v x u Apparently, the answer is -74 but I keep getting some other weird answer.. Thanks if you can h      Log On


   

Question 973307: Let u= <5,-3> and v=<-2,9> be vectors. Find this indicated expression:
2v x u
Apparently, the answer is -74 but I keep getting some other weird answer.. Thanks if you can help.
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
Let u= <5,-3> and v=<-2,9> be vectors
2v = <-4,18>, then
the cross product of 2v and u is
<-4,18> x <5,-3> = (-4*-3) - (18*5) = 12 - 90 = -78