Jawabanmu

2014-02-25T04:09:02+07:00
A. X1²+X2²=(X1+X2)²-2X1X2 = (2)² - 2(-2) = 4 + 4 = 8
b. \frac{x1}{x2} + \frac{x2}{x1} = \frac{x1^2 + x2^2}{x1.x2}   \\ 
                                           =  \frac{8}{-2} = -4
c.  \frac{1}{x1} +  \frac{1}{x2} =  \frac{x1+x2}{x1.x2} = \frac{2}{-2} = -1