Answer:
second option
Step-by-step explanation:
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex]
Simplifying the radicals
[tex]\sqrt{27x^{3} }[/tex]
= [tex]\sqrt{9(3)x^2.x}[/tex]
= [tex]\sqrt{9}[/tex] × [tex]\sqrt{3}[/tex] × [tex]\sqrt{x^2}[/tex] × [tex]\sqrt{x}[/tex]
= 3 × [tex]\sqrt{3}[/tex] × x × [tex]\sqrt{x}[/tex]
= 3x[tex]\sqrt{3x}[/tex]
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[tex]\sqrt{12x^{3} }[/tex]
= [tex]\sqrt{4(3)x^2.x}[/tex]
= [tex]\sqrt{4}[/tex] × [tex]\sqrt{3}[/tex] × [tex]\sqrt{x^2}[/tex] × [tex]\sqrt{x}[/tex]
= 2 × [tex]\sqrt{3}[/tex] × x × [tex]\sqrt{x}[/tex]
= 2x[tex]\sqrt{3x}[/tex]
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Thus
3 × 3x[tex]\sqrt{3x}[/tex] - 2 × 2x[tex]\sqrt{3x}[/tex]
= 9x[tex]\sqrt{3x}[/tex] - 4x[tex]\sqrt{3x}[/tex]
= 5x[tex]\sqrt{3x}[/tex]
