Need help to solve PMT with detailed explanation cause my textbook got me confused

Given:
[tex]\frac{100000*(\frac{0.09}{12})}{1-(1+\frac{0.09}{12})^{(-12*15)}}[/tex]Required:
Simplify the given
Explanation:
[tex]\frac{100000*0.0075}{1-(1.0075)^{-180}}=\frac{750}{1-0.2605}=\frac{750}{0.739}\approx1013.51[/tex]Final answer:
1013.51