a) \(\left(x^2-7x+12\right).\left(x^2-15x+56\right)-60\)
\(=\left(x-3\right)\left(x-4\right)\left(x-7\right)\left(x-8\right)-60\)
b) \(x^4+2000x^2+1999x+2000\)
\(=\left(x^2-x+2000\right)\left(x^2+x+1\right)\)
\(=\left(x^2+x-1\right)^2+1999\left(x^2+x+1\right)+1\)
hình như Thành lộn đề rồi đấy ạ, ý mình là phân tích thành nhân tử á
b) \(x^4+2000x^2+1999x+2000\)
\(=x^4-x+2000x^2+2000x+2000\)
\(=x\left(x^3-1\right)+2000\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2000\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x-2000\right)\)
a) Đặt \(P=\left(x^2-7x+12\right)\left(x^2-15x+56\right)-60\)
\(P=\left(x-3\right)\left(x-4\right)\left(x-7\right)\left(x-8\right)-60\)
\(P=\left(x-3\right)\left(x-8\right)\left(x-4\right)\left(x-7\right)-60\)
\(P=\left(x^2-11x+24\right)\left(x^2-11x+28\right)-60\)
\(P=\left(x^2-11x+26\right)^2-4-60\)
\(P=\left(x^2-11x+26\right)^2-64\)
\(P=\left(x^2-11x-18\right)\left(x^2-11x+34\right)\)