How do you solve this equation: [math]0.4 = \frac{\frac{120!}{ (120-n)!}}{ 120 ^n}[/math]?
Why does solving [math]5x+3y+7z=4, \; 3x+26y+2z=9[/math] and [math]7x+2y+10z=5[/math] using fx-991ESplus, gives me math error even though solution of these equations exist and it is [math]x= \frac{7}{11} ,y= \frac{3}{11} , z=0?[/math]