1) 21(18+х)=714
2) 16(4х-34)=608
3) 12(152+19х)=2052
4) (152х+32)*6=192

Спасибо большое 

1) 21(18+х)=714 18+x=714:2118+x=34x=34-18x=16========= 2) 16(4х-34)=6084x-34=608:164x-34=384x=38+344x=72x=72:4x=9=========== 3) 12(152+19х)=2052152+19x=2052:12152+19x=17119x=171-15219x=19x=19:19x=1============== 4) (152х+32)*6=192 152x+32=192:6152x+32=32152x=32-32152x=0x=0