The answer is: [tex]13-\frac{2}{9}g[/tex]
The explanation is shown below:
1- You have the following expression given in the exercise:
[tex](\frac{30}{45}g+20)-(\frac{8}{9}g+7)[/tex]
2- When you multiply signs, you obtain:
[tex]\frac{30}{45}g+20-\frac{8}{9}g-7[/tex]
3. Now, you must add like terms, as following:
[tex]-\frac{2}{9}g+13[/tex]
4. Therefore, you have that the expression simplified is:
[tex]13-\frac{2}{9}g[/tex]