(40,000-3000-(-18,000+10000))*1-0.4
=25,400
HOW??
\((40,000-3000-(-18,000+10000))\times1-0.4\\ = 40000 - 3000 + 18000 - 10000-0.4\\ =45000 - 0.4\\ = 44999.6\\ \text{It doesn't equal 25400}\)
