Anna is very weak. I don't she can do his job (sử dụng enough)

2 chân

3^7. 16^3=3^7. (2^4)^3       =3^7.2^12            =3^2.2^2=2^2    =4

12^5.21^3=(3.2^2)^5.(7.3)^3=3^5.2^10.7^3.3^3=7^3.3^3=343.3=1029

to giai o duoi ay

\(3x^4-4x^3+1\)

\(=3x^4+2x^3+x^2-6x^3-4x^2-2x+3x^2+2x+1\)

\(=x^2\left(3x^2+2x+1\right)-2x\left(3x^2+2x-1\right)+\left(3x^2+2x+1\right)\)

\(=\left(x^2-2x+1\right)\left(3x^2+2x+1\right)\)

\(=\left(3x^2+2x+1\right)\left(x-1\right)^2\)