$2\left(x+5\right)=18+x$  

(a)  

 $2\left(2x+1\right)=3x+5$  

(a)  

 $2\left(2x+3\right)=x+18$  

(a)  

 $\Delta\Delta\ +2=14$  

(a)  

 $20=\Delta\Delta+6$  

(a)  

 $x+6=2x+1$  

(a)  

 $x+2x+x+x+3=8$  

(a)  

 $3x+3=x+21$  

(a)  

 $4x-2x+1=2x+2x-x$  

(a)