\begin{tabular}{l} Simplify the following: \\ \( \qquad \frac{7 x^{2}}{3}-\frac{9 x^{2}}{7}-\frac{x^{2}}{21} \) \\ Answer: \\ \hline Check answer 2 attempts remaining \\ \hline\end{tabular}

Calculate or simplify the expression \( \frac{7x^2}{3}-\frac{9x^2}{7}-\frac{x^2}{21} \). Simplify the expression by following steps: - step0: Solution: \(\frac{7x^{2}}{3}-\frac{9x^{2}}{7}-\frac{x^{2}}{21}\) - step1: Reduce fractions to a common denominator: \(\frac{7x^{2}\times 7}{3\times 7}-\frac{9x^{2}\times 3}{7\times 3}-\frac{x^{2}}{21}\) - step2: Multiply the numbers: \(\frac{7x^{2}\times 7}{21}-\frac{9x^{2}\times 3}{7\times 3}-\frac{x^{2}}{21}\) - step3: Multiply the numbers: \(\frac{7x^{2}\times 7}{21}-\frac{9x^{2}\times 3}{21}-\frac{x^{2}}{21}\) - step4: Transform the expression: \(\frac{7x^{2}\times 7-9x^{2}\times 3-x^{2}}{21}\) - step5: Multiply the terms: \(\frac{49x^{2}-9x^{2}\times 3-x^{2}}{21}\) - step6: Multiply the terms: \(\frac{49x^{2}-27x^{2}-x^{2}}{21}\) - step7: Subtract the terms: \(\frac{21x^{2}}{21}\) - step8: Divide the terms: \(x^{2}\) The simplified expression is \(x^2\).