Can somebody work out this problem -3x+9=6

Fast phone couldn’t copy and paste so i decided to right it down

Svetlana's hair is 4 4 centimeters ( cm cm) long. her hair grows 1 . 5 cm 1.5cm per month. svetlana wants her hair to be less than 1 6 cm 16cm long. write an inequality to determine the number of months, m m, svetlana can allow her hair to grow so that it is less than 1 6 cm 16cm long.

2.5 milligrams is equivalent to how many grams