Find the zero(s) of \( f(x)=8.53 x^{2}-9.81 x-5.69 \) to three decimal places. If there is more than one zero, write all them on the same line, separated by commas.

Solve the equation \( 8.53x^{2}-9.81x-5.69=0 \). Solve the quadratic equation by following steps: - step0: Solve using the quadratic formula: \(8.53x^{2}-9.81x-5.69=0\) - step1: Convert the decimal into a fraction: \(\frac{853}{100}x^{2}-\frac{981}{100}x-\frac{569}{100}=0\) - step2: Multiply both sides: \(100\left(\frac{853}{100}x^{2}-\frac{981}{100}x-\frac{569}{100}\right)=100\times 0\) - step3: Calculate: \(853x^{2}-981x-569=0\) - step4: Solve using the quadratic formula: \(x=\frac{981\pm \sqrt{\left(-981\right)^{2}-4\times 853\left(-569\right)}}{2\times 853}\) - step5: Simplify the expression: \(x=\frac{981\pm \sqrt{\left(-981\right)^{2}-4\times 853\left(-569\right)}}{1706}\) - step6: Simplify the expression: \(x=\frac{981\pm \sqrt{981^{2}+1941428}}{1706}\) - step7: Separate into possible cases: \(\begin{align}&x=\frac{981+\sqrt{981^{2}+1941428}}{1706}\\&x=\frac{981-\sqrt{981^{2}+1941428}}{1706}\end{align}\) - step8: Rewrite: \(x_{1}=\frac{981-\sqrt{981^{2}+1941428}}{1706},x_{2}=\frac{981+\sqrt{981^{2}+1941428}}{1706}\) The zeros of the function \( f(x)=8.53x^{2}-9.81x-5.69 \) to three decimal places are approximately -0.424 and 1.574.