Assume the return of a stock from t to t+1 is 10%. 1. Consider two scenarios: a. without any leverage: invest 100 yuan into this stock, what is the return from t to t+1 on the stock ? (we denote such return as ra, and we denote the corresponding as a) b. with leverage: assume the initial capital is 100 yuan and 900 yuan is the maximum amount you can borrow; what could be the return if you all the money(1000 yuan) into this stock, assuming the risk-free rate is 0% ? (we denote such return as rb, and we denote the corresponding as b b) 2. what is the relation between ra and rb, please describe this relation with one-line equation 3. what is the relation between a and b ? please describe it using one-line equation. 4. According to results discussed above, after taking leverage, how would the of your investment change (increase or decrease)