(1 point) In a grid of wires, the temperature at exterior mesh poins is maintained at constant values as shown in the figure. When the grid is in thermal equilibrium, the temperature at each interior mesh point is the average of the temperatures at the four adjacent points. For instance, _ T2+T3+20180 T1 4 Find the temperatures T1, T2, T3, T4, when the grid is in thermal equilibrium. T1 = T2 = T3 = :1 n mm Ian