Use the determinant of the coefficient matrix to determine which of the following linear systems have unique solutions.

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

An equation in slope-intersept form the lines that passes thought (-8,1) and is perpindicular to the y=2x-17.

If a suspect is in possession of 20 grams of cocaine how many ounces does he possess what will the charge be