The first floor of a real estate is a garage (not for external sales), and the second to twenty-third floors are all commercial houses (for external sales). The price scheme of commercial housing is a

The first floor of a real estate is a garage (not for external sales), and the second to twenty-third floors are all commercial houses (for external sales). The price scheme of commercial housing is as follows: starting from the eighth floor, Solution: (1) When 2≤x≤8, the price per square meter should be: 3000-(8-x)×20=20x+2840 (yuan/square meter) When 9≤x≤23, The price per square meter should be: 3000+(x-8)40=40x+2680 (yuan/square meter) ∴ Y = 20x+2840 (2 ≤ x ≤ 8) 40x+2680 (9 ≤ x ≤ 23). Xiao Zhang's down payment is (20x+2840). Xiao Zhang's down payment is (40x+2680)12030% = 36 (40x+2680) yuan 36(40x+2680)≤ 120000, and the solution is: x≤49÷3, ∫x is a positive integer. Then the actual house price of Lao Wang is: y1= (4016+2680)12092%-60a (Yuan). According to Lao Wang's idea, the house payment is y2 = (4016+2680) y1-y2 > 0. When y 1≤y2 represents y 1-y2≤0, the solution is a≥66.4. At this time, Lao Wang's idea is not correct.