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Is x>0?
1) x^2=9x
2) x^2=81
OA C
Source: Veritas Prep
1) x^2=9x
2) x^2=81
OA C
Source: Veritas Prep
1) \(x^2=9x \Rightarrow x^2-9x =0 \Rightarrow x(x-9)=0\)BTGmoderatorDC wrote: ↑Sun Jun 26, 2022 10:59 pmIs x>0?
1) x^2=9x
2) x^2=81
OA C
Source: Veritas Prep
\(x\) can be \(0\) or \(9\). No Sufficient \(\Large{\color{red}\chi}\)
2) \(x^2=81 \Rightarrow x^2-81=0 \Rightarrow (x-9)(x+9)=0\)
\(x\) can be \(-9\) or \(9\). Not Sufficient \(\Large{\color{red}\chi}\)
Combining 1) and 2)
\(x\) is definitely \(9\). Sufficient \(\Large{\color{green}\checkmark}\)
Therefore, C
