Question

-Giải hộ mik bài này vs!!

a^4+3a^3+12a-16

Answer 1

\(a^4+3a^3+12a-16\\ \\ =\left(a^4-16\right)+\left(3a^3+12a\right)\\ \\ =\left(a^2+4\right)\left(a^2-4\right)+3a\left(a^2+4\right)\\ \\ =\left(a^2+4\right)\left(a^2-4+3a\right)\\ =\left(a^2+4\right)\left(a^2-4+a-4a\right)\\ \\ =\left(a^2+4\right)\left[\left(a^2+a\right)-\left(4a+4\right)\right]\\ =\left(a^2+4\right)\left[\left(a^2+a\right)-\left(4a+4\right)\right]\\ \\ =\left(a^2+4\right)\left[a\left(a+1\right)-4\left(a+1\right)\right]\\ \\ =\left(a^2+4\right)\left(a-4\right)\left(a+1\right)\)