$\left|-47\right|-\left|-19\right|=$  

(a)  

 $\left|-17\right|-\left|+8\right|=$  

(a)  

 $\left|-30\right|-\left|-12\right|=$  

(a)  

 $-\left(-12\right)=$  

(a)  

 $+\left(-15\right)=$  

(a)