Find Unit 1 first. The first unit is the total expenditure, but it is unknown. So by division, we can get that the first unit uses 270 ÷ (40%-25%) = 270 ÷15% = 270 ÷ 0.15 =

First, the expenditure amounts of these two expenses are calculated:1800× (40%+25%) =1270 (yuan), 1800- 1270 = 530 (yuan), so other expenses are 530 yuan.