The dogs are going to be labeled x. This problem can be represented by the equation 4x+x=30, because there are 30 dogs total and 4x is the boxers and x is the spaniels. We then solve for x, 5x=30, x=6. Then we can plug this x value into the equations for boxers and spaniels, finding that there are 24 boxers and 6 spaniels.