Are the lines X - 2Y= 4 and Y = 2X -2 parallel perpendicular or neither?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Awavelength of 610 nm was found to be the most intense wavelength emitted by copper. answer the following questions about this wavelength of light. a) what is this wavelength in cm? b) what is the frequency that corresponds to this wavelength? c) what is the energy of light of this wavelength? d) what is the wavenumber corresponding to this wavelength?

Keith runs 5 miles in 38 minutes. at the same rate, how many miles would he run in 57 minutes