You are not allowed to pay for each card, but you have to deduct 5 yuan, so you have to deduct 5x yuan.
Safe operation of 500-x flowerpot.
The money for every 0.2 is 0.2(500-x).
The money deducted from the earned money is equal to the last earned money.
0.2(500 x)-5x = 74
X=5 when solving the equation.
Broke five flower pots.