(1)8a³b²-12ab³c=4ab²(2a²-3bc)
(2)-49x²+36y²=(6y+7x)(6y-7x)
(3)x²+6x+9=(x+3)²
(4)5(x-y)³+10(y-x)²
=5(x-y)³+10(x-y)²
=5(x-y)²(x-y+2)
①8a^3*b^2-12ab^3*c =4ab²(2a²-3bc)
②-49x^2+36y^2=(6y-7x)(6y+7x)
③x^2+6x+9=(x+3)²
④5(x-y)^3+10(y-x)^2 =5(x-y)²(x-y+2)