A vector w has components <4, 9>. If we multiply it by a scalar and the resultant components are <-8, -18>, what is the scalar?
We need to figure out which number both the components of w were multiplied by to get -8 and -18. We could either divide the components of the final vector by those of the original vector, or use trial and error with every answer choice. Regardless, multiplying both the 4 and the 9 of the original vector by -2 will get us the components of the resultant vector.