CFA會計的問題 3 - 金融分析師

一個在Schweser study Book 3 p324頁Income tax的問題請教一下
題目如下

---A firm acquires an asset for $120,000 with a 4-year useful life
and no salvage value
---The asset will generate $50,000 of cash flow for all four years
---The tax rate is 40% each year
---The firm will depreciate the asset over three years
on a straight-line (SL) basis for tax purposes and
over all four years on a SL basis for financial reporting purposes


問題：
suppose tax rates rise during year 2 to 50%
What will be the income tax expense in year 2



答案是$11,000

我個人的計算是$9,000
我是把第一年的tax deferred liability 4,000
加上第二年的tax deferred liability 5,000
4,000 + 5,000 = 9,000


但是解答是5,000+(10,000-4,000)=11,000
公式是Tax expense=tax payable + tax deferred liability
第二年的部分是5,000沒有問題
但是我搞不懂的是為什麼會有10,000-4,000的差異



是不是有人可能糾正我錯誤的觀念呢
謝謝

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