24-12+6-3 cara menghitung deret geometri tak hingga?

a = 24, b =-2


deret tak hingga nya
[tex] \frac{a}{1 - r} \\ = \frac{24}{1 - ( - \frac{1}{2}) } \\ = \frac{24}{1 + \frac{1 }{2} } \\ = \frac{24}{ \frac{3}{2} } \\ = 24. \frac{2}{3} \\ = \frac{48}{3} \\ = 16[/tex]