4·(3х-2у)²-9·(4х+3у)²=(2·(3x-2y))²-(3·(4x+3y))²=[формула разности квадратов]=
(2·(3х-2у)-3·(4х+3у))·(2·(3х-2у)+3·(4х+3у))=(6х-4у-12х-9у)·(6х-4у+12х+9у)=
=(-6х-13у)·(18х+5у)=-108х²-234ху-30ху-65у²=-108х²-264ху-65у²
100·(6а+3b)²-81·(3a+2b)²=(10·(6a+3b))²-(9·(3a+2b))²=
=(10·(6a+3b)-9·(3a+2b))·(10·(6a+3b)+9·(3a+2b))=
=(60a+30b-27a-18b)·(60a+30b+27a+18b)=(33a+12b)·(87a+48b)=
=2871a²+1044ab+1584ab+576b²=2871a²+2628ab+576b²
49·(5x²+8)²-36·(4x²+1)²=(7·(5x²+8))²-(6·(4x²+1))²=
(7·(5x²+8)-6·(4x²+1))·(7·(5x²+8)+6·(4x²+1))=(35x²+56-24x²-6)·(35x²+56+24x²+6)=
=(11x²+50)·(59x²+62)=649x⁴+2950x²+682x²+3100=649x⁴+3632x²+3100