Question

关于盈利亏损的问题（初一,需列方程）

Answer 1

1) 90 - 0.6 x = 30 => x = 100

2)

200 * 0.3 - 55 = 5 > 0 不亏损

200 * 0.2 - 55 = -15 < 0 亏损

3)

x (1+30%) 80% = 208 => x=200