Define the variables. Write the equations for the populations of the schools over time in y = mx + b form.
The equation that represents the population of Tehachapi High School over time is y = 34x + 839, because the growth is 34 students (m) and it started at 834 students (b). Now write the equation for Fresno High.
Once you have both equations you have a system of equations. So solve by using the Equal Values method.
Check your answer!