Hi Jacob,
Let
H = # hamburgers sold
D = # hot dogs sold
H + D = 486
3H + 2D = 1218
We can use elimination or substitution to solve
To use elimination, we need to multiply the first equation by -3. This will eliminate the H
The first equation becomes
-3H - 3D = -1458
3H + 2D = 1218
Adding these equations together, we have
-D = -240
and
D = 240
So 240 hot dogs were sold