When the price of electrical appliances is more than 500 and less than 1000, shopping mall B has a discount, so shopping mall B is selected.
When the price of electrical appliances is greater than 1000, let the price be x1000+(x-1000) * 0.9 = 500+(x-500) * 0.95.
0.9x+ 1000 * 0. 1 = 500 * 0.05+0.95 x
500 * 0. 15 = 0.05 times.
x= 1500
Therefore, when the price is greater than 1000 and less than 1500, it is still the discount of mall B.
When the price is equal to 1500, the discount range of the two shopping malls is the same.
When the price is greater than 1500, there are shopping malls to provide discounts.