а)(b-5)(b-4)-3b(2b-3)=b^2-4b-5b+20-6b^2+9b=-4b^2+20=4(-b^2+5)
Б)3x(x-2)-(x-3)²= 3x^2-6x-x^2+6x-9=2x^2-9=2(x^2-4.5)
в)5(a+1)²-10a=5a^2+10a+5-10a=5a^2+5=5(a^2+1)
а)3c³-75c=3c(c^2-25)
б)3x²+6xy+3y²=3(x^2+2xy+y^2)=3(x+y)^2
в)x³+8=x^3+2^3=x^3+6x^2+12x+8
(y²+6y)²-y²(6+5y)(6-5y)-y²(12y-y²)=y^4+12y^3+36y^2-36y^2+25y^4-12y^3+y^4=27y^4
а)(a-b)²-a²=a^2-2ab+b^2-a^2=-2ab+b^2
б)x³+y³+2xy(x+y)=x^3+y^3+2x^2y+2xy^2=(x+y)^3