a) \(A\in Z< =>10⋮\left(\sqrt{x}+3\right)\)
mà \(\sqrt{x}\ge\ge0< =>\sqrt{x}+3\ge0< =>\sqrt{x}-3\in\left\{5;10\right\}\)
\(\sqrt{x}+3=5< =>\sqrt{x}=2< =>x=4\)
\(\sqrt{x}=3=10< =>\sqrt{x}=7< =>x=49\)
b) \(P\in Z< =>5⋮\left(3\sqrt{x}+2\right)\)
mà \(3\sqrt{x}+2\ge2=>3\sqrt{x}+2=5< =>3\sqrt{x}=3< =>\sqrt{x}=1< =>x=1\)