Create an equation for each model.
y = 12,000 + 0.10x
y = 14,000 + 0.08x
Set them equal to each other and solve to find when they will be the same.
12,000 + 0.10x = 14,000 + 0.08x
0.10x = 2,000 + 0.08x
0.02x = 2,000
x = 100,000
They will be the same after 100,000 miles.