Question

Answer 1

giúp mình nhanh nha mn

 

Answer 2

Bài 2:

\(a,A\left(x\right):B\left(x\right)=\left(4x^3-2x^2+6x^2-3x+8x-4+4+a\right):\left(2x-1\right)\\ =\left[2x^2\left(2x-1\right)+3x\left(2x-1\right)+4\left(2x-1\right)+4+a\right]:\left(2x-1\right)\\ =2x^2+3x+4\left(\text{dư }a+4\right)\\ b,A\left(x\right)⋮B\left(x\right)\Leftrightarrow a+4=0\Leftrightarrow a=-4\)

Bài 3:

\(\left(x+1\right)\left(x+3\right)\left(x+5\right)\left(x+7\right)-20\\ =\left(x^2+8x+7\right)\left(x^2+8x+15\right)-20\\ =\left(x^2+8x+11\right)^2-16-20\\ =\left(x^2+8x+11\right)^2-36\\ =\left(x^2+8x+17\right)\left(x^2+8x-5\right)\)