Question

||8х+1|-2|=9
|4+|5х+2||=9
||10х+7|-5|=13

Answer 1

1. $||8x+1|-2|=9\\|8x+1|-2=9\\|8x+1|-2=-9\\x_1=\frac{-3}{2}; x_2=\frac{5}{4}$  
2. $|4+|5x+2||=9\\|5x+2|=5\\5x+2=5; 5x+2=-5\\x_1=\frac{-7}{5} ;x_2=\frac{3}{5}$  
3. $||10x+7|-5|=13\\|10x+7|-5=13; |10x+7|-5=-13\\x_1=-\frac{5}{2}; x_2=\frac{11}{10}$