1. (3х+4)(х-10)+(10-х)(х-8)=0
(3х+4)(х-10)-(х-10)(х-8)=0
(х-10)(3х+4-(х-8))=0
(х-10)(3х+4-х+8)=0
(х-10)(2х+12)=0
2(х-10)(х+6)=0
1) х-10=0; х₁=10
2) х+6=0; х₂= -6
2. 3(3х+1)²-4(3х+1)=0
(3х+1)(3(3х+1)-4)=0
(3х+1)(9х+3-4)=0
(3х+1)(9х-1)=0
1) 3х+1=0; 3х= -1; х₁= -1/3
2) 9х-1=0; 9х=1; х₂=1/9