Question

giúp mình vs ạ !

Answer 1

\(\sqrt{9a^4}+2a^2=\sqrt{\left(3a^2\right)^2}+2a^2=\left|3a^2\right|+2a^2=3a^2+2a^2=5a^2\)

\(\sqrt{9x^2}-2x=\sqrt{\left(3x\right)^2}-2x=\left|3x\right|-2x=3x-2x=x\)

\(\sqrt{4-2\sqrt{3}}-\sqrt{3}=\sqrt{\left(\sqrt{3}-1\right)^2}-\sqrt{3}=\left|\sqrt{3}-1\right|-\sqrt{3}=\sqrt{3}-1-\sqrt{3}=-1\)

\(3-x+\sqrt{x^2+6x+9}=3-x+\sqrt{\left(x+3\right)^2}=3-x+\left|x+3\right|=3-x+x+3=6\)

Answer 2

a) \(\sqrt{9a^4}+2a^2=3a^2+2a^2=5a^2\)

c) \(\sqrt{4-2\sqrt{3}}-\sqrt{3}=\sqrt{3}-1-\sqrt{3}=-1\)

d) \(3-x+\sqrt{x^2+6x+9}=3-x+x+3=6\)