Question

aratati ca nu depinde de x :. a=(x+2)^2-x(x+4)​

Answer 1

$\displaystyle\bf\\a=(x+2)^2-x(x+4)=x^2+4x+4-x^2-4x=4,~(am~redus~termenii).\\\boxed{\bf (m\pm n)^2=m^2 \pm 2mn + n^2}~.$