Tentukan akar-akar persamaan kuadrat berikut dengan cara melengkapi kuadrat sempurna

<p>a. x² - 64 = 0</p><p>&nbsp; &nbsp; &nbsp;x² = 64</p><p>&nbsp; &nbsp; &nbsp;x = ±√64</p><p>&nbsp; &nbsp; &nbsp;x = ±8</p><p>&nbsp; &nbsp; &nbsp;x₁ = -8 atau x₂ = -8</p><p>&nbsp;&nbsp;</p><p>b. x² - 6x + 7 = 0</p><p>&nbsp; &nbsp; &nbsp;x² - 6x = &nbsp;-7&nbsp;</p><p>&nbsp; &nbsp; &nbsp;x² - 6x + (-6/2)² = &nbsp;-7 + (-6/2)²&nbsp;</p><p>&nbsp; &nbsp; &nbsp;x² - 6x + (-3)² = &nbsp;-7 + (-3)²&nbsp;</p><p>&nbsp; &nbsp; &nbsp;x² - 6x + 9 = &nbsp;-7 + 9</p><p>&nbsp; &nbsp; &nbsp;x² - 6x + 9 = &nbsp;2</p><p>&nbsp; &nbsp; &nbsp;(x - 3)² = 2</p><p>&nbsp; &nbsp; &nbsp; x - 3 = ±√2</p><p>&nbsp; &nbsp; &nbsp; x = 3 ± √2</p><p>&nbsp; &nbsp; &nbsp; x₁ = 3 + √2 atau x₂ = 3 - √2</p><p>&nbsp;</p><p>c. 2x² + 3x - 20 = 0</p><p>&nbsp; &nbsp; &nbsp;2x² + 3x &nbsp;= 20</p><p>&nbsp; &nbsp; &nbsp;x² + 3/2 x = 10 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(masing-masing ruang dibagi 2)</p><p>&nbsp; &nbsp; &nbsp;x² + 3/2 x + (3/4)²= 10 + (3/4)^2&nbsp;</p><p>&nbsp; &nbsp; &nbsp;x² + 3/2 x + 9/16= 10 + 9/16</p><p>&nbsp; &nbsp; &nbsp;x² + 3/2 x + 9/16= 160/16 + 9/16</p><p>&nbsp; &nbsp; &nbsp; x² + 3/2 x + 9/16= 169/16</p><p>&nbsp; &nbsp; &nbsp; (x + 3/4)² = 169/16</p><p>&nbsp; &nbsp; &nbsp; x + 3/4 = ±√(169/16)</p><p>&nbsp; &nbsp; &nbsp; x + 3/4 = ± 13/4</p><p>&nbsp; &nbsp; &nbsp; x = -3/4 ± 13/4</p><p>&nbsp; &nbsp; &nbsp; &nbsp;x₁ = -3/4 + 13/4 = 10/4 =<strong> 5/2</strong></p><p>&nbsp; &nbsp; &nbsp; &nbsp; atau</p><p>&nbsp; &nbsp; &nbsp; &nbsp;x₂ = &nbsp;-3/4 - 13/4 = -16/4 = <strong>-4</strong></p><p>&nbsp; &nbsp; &nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>