a: A=B
\(\Leftrightarrow x^2+x-6-10x+5-x^2+2x-1=0\)
\(\Leftrightarrow-7x-2=0\)
hay x=-2/7
b: A=B
\(\Leftrightarrow x^3+1-6x-2=x^3-x\)
=>-6x-1=-x
=>-5x=1
hay x=-1/5
c: A=B
\(\Leftrightarrow x^2+4x+4-x^2+1-4x-2=3\)
=>3=3(luôn đúng)
d: A=B
\(\Leftrightarrow x^3-3x^2+3x-1-\left(x^3-6x^2+12x-8\right)=3x^2-9x+5\)
\(\Leftrightarrow x^3-3x^2+3x-1-x^3+6x^2-12x+8-3x^2+9x-5=0\)
=>2=0(vô lý)