Physics summer assignment vector multiplication

[grosenblatt]

Homework Statement

In the product (Vector F) = q(Vector v) X (Vector B), take q = 2,
(Vector v) = 2.0i + 4.0j + 6.0k
(Vector F) = 4.0i - 20j + 12k

What than is (Vector B) in unit-vector notation if Bx = By

Homework Equations

dot and cross products

The Attempt at a Solution

4.0i - 20j + 12k = (8_yb_z - 12_zb_y)i + (12_zb_x - 4_xb_z)j + (4_xb_y - 8_yb_x)k

 

[grosenblatt]

can anyone help? this is due tommorow =(. i really just don't know where to go from here at all