Question

simply vectors:
for which value of x are the vectors (-4, x) and (2, -3) parallel?

Answer 1

These vectors are paralel if exists a constant C that you may write:
(-4,x) = C .(2,-3)

It gives you the following linear system:

-4=2C -> C=-2
x=C.-3

Replacing C --> x=6

so: (-4, 6) // (2,-3)

Answer 2

parallel lines must have same slope
slope is dy/dx
=> -3/2 = x/-4
=> 2x = 12
=> x=6

Answer 3

ooh, two ways of doing it... and both end up with the same answer.

thanks