Please see my comment to the question. In both cases, this is not a problem for gradate students. It means the solution of linear equations which is a work for middle school or early high school student (it depends on your school system, but it requires level well below the required entry level of a college, university or a technical school student). It's reduced to the ability to solve equations like
X<sub>1</sub> = X<sub>0</sub> + K × X<sub>2</sub><br />
Y<sub>1</sub> = Y<sub>0</sub> + K × Y<sub>2</sub><br />
Wake up and solve them.