Question

Answer 1

Câu 2:

\(a,A=4-6x+2x^2-3x^3\\ b,B=xy+2xy^2-4\)

Câu 3:

\(a,C=3y\left(x^2+2x+1\right)=3y\left(x+1\right)^2\\ D=16y^2-\left(2x+3\right)^2=\left(4y-2x-3\right)\left(4y+2x+3\right)\\ b,\Leftrightarrow x^3-x^2-7x+m=\left(x-3\right)\cdot a\left(x\right)\)

Thay \(x=3\Leftrightarrow27-9-21+m=0\Leftrightarrow m=3\)

Câu 4:

\(a,ĐK:x\ne0;x\ne-4\\ b,P=\dfrac{\left(x+4\right)^2}{x\left(x+4\right)}=\dfrac{x+4}{x}\\ c,P=0\Leftrightarrow x+4=0\Leftrightarrow x=-4\left(ktm\right)\Leftrightarrow x\in\varnothing\)

Answer 2

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