原式=23.9×（3.5+6.5）=23.9×10=239
-2/9×（-92）+（-2/9×34 3/5+2/9×23 3/5） =2/9×92-2/9×(34*5+3)/5+2/9×(23*5+3)/5 =2/9×(92-34-3/5+23+3/5) =2/9×81 =16
