Could you please help me to solve the following question?

"Purchased equipment costing $6,320, paying $4,893 in cash and charging the rest on account. How does this transaction affect to the equations A=L+SE and NI=R-E"

The answer seems A=+6,320-4,893=+1,427, L=+1,427, SE,NI,R,E=no effect

However, I thought the equipment should be recorded as expense therefore A=-4,893, L=+1,427, SE=-6,320, R=+6,320

Why is the equipment not recorded as expense???