Answer:
x = 
Step-by-step explanation:
(x + 6 )^2 = 49
get rid of the square , by square rooting the 49
x + 6 = 
x =
-6
x = 
means + or - hence it could be -7 -6 = -1 ... or 7-6 = 1
therefore the answer is = or - 1
hence in terms of roots .. answer is :

If the rectangle has a fixed width of 300, it means that

where
and
are width and length, respetively.
So given the length
, the are would be

The cross product of two vectors gives a third vector

that is orthogonal to the first two.

Normalize this vector by dividing it by its norm:

To get another vector orthogonal to the first two, you can just change the sign and use

.