公式应该是asset*beta_asset=debt*beta_debt+equity*beta_equity
没理解怎么得出，视频讲解的时候应该也没有提到这个知识点
问题如下图：
选项：
A. 
B. 
C. 
解释：
NO.PZ2016021705000028 问题如下 Wang Securities ha long-term stable bt-to-equity ratio of 0.65. Recent bank borrowing for expansion into South Ameriraisethe ratio to 0.75. The increaseleverage hwheffeon the asset beta anequity beta of the company? A.The asset beta anthe equity beta will both rise. B.The asset beta will remain the same anthe equity beta will rise. C.The asset beta will remain the same anthe equity beta will cline. is correct.Asset risk es not change with a higher bt-to-equity ratio. Equity risk rises with higher bt. 题目告知E=0.65（假设0.65，E=1），变为E=0.75（假设0.75，E=1）.为什么βa不变？在βa不变的情况下，由公式E*βe=A*βa=（（1-T）+E）*βa，可以得出，当E=0.65变为E=0.75时，βe变大。\"βe变大\",可以理解。想知道为什么当E=0.65变为E=0.75时，βa不变？
NO.PZ2016021705000028 问题如下 Wang Securities ha long-term stable bt-to-equity ratio of 0.65. Recent bank borrowing for expansion into South Ameriraisethe ratio to 0.75. The increaseleverage hwheffeon the asset beta anequity beta of the company? A.The asset beta anthe equity beta will both rise. B.The asset beta will remain the same anthe equity beta will rise. C.The asset beta will remain the same anthe equity beta will cline. is correct.Asset risk es not change with a higher bt-to-equity ratio. Equity risk rises with higher bt. 如果E 比例增加 (由 0.65 增加到 0.75) 那代表bt增加 equty不变或者变小的话值才能增加啊。为啥equty要跟着变大
NO.PZ2016021705000028问题如下Wang Securities ha long-term stable bt-to-equity ratio of 0.65. Recent bank borrowing for expansion into South Ameriraisethe ratio to 0.75. The increaseleverage hwheffeon the asset beta anequity beta of the company?A.The asset beta anthe equity beta will both rise.B.The asset beta will remain the same anthe equity beta will rise.C.The asset beta will remain the same anthe equity beta will cline.is correct.Asset risk es not change with a higher bt-to-equity ratio. Equity risk rises with higher bt.根据红色圈圈的公式，比率的变化不是应该影响asset beta吗？不是很理解麻烦老师讲解下
NO.PZ2016021705000028 问题如下 Wang Securities ha long-term stable bt-to-equity ratio of 0.65. Recent bank borrowing for expansion into South Ameriraisethe ratio to 0.75. The increaseleverage hwheffeon the asset beta anequity beta of the company? A.The asset beta anthe equity beta will both rise. B.The asset beta will remain the same anthe equity beta will rise. C.The asset beta will remain the same anthe equity beta will cline. is correct.Asset risk es not change with a higher bt-to-equity ratio. Equity risk rises with higher bt. AxβA=ExβE 由于A不变 所以左边不变 右边由于E的上升导致E的权重变小了 所以E变小 βE变大
NO.PZ2016021705000028 The asset beta will remain the same anthe equity beta will rise. The asset beta will remain the same anthe equity beta will cline. is correct. Asset risk es not change with a higher bt-to-equity ratio. Equity risk rises with higher bt.bt-to- equity ratio是什么意思呀？这个比率表示什么杠杆呀？
