Question

Let u= and v=<1-4x, 20>. If u is parallel to v, find x.

Answer 1

\[u= <x+2,-8>, v=<1-4 x ,20> \]
\[x+2(-20/8) = 1-4x\]
\[-20(x+2)=8-32x\]
\[12x=48\]
\[x=4\]

Since the vectors are parallel, they should be a multiple of one another, find that multiple for one of the two vectors. Set the vectors equal to one another and solve for x.