Explanation:
x² - 4x - 9 = 29
Collect like terms:
x² - 4x - 9 - 29 = 0
x² - 4x - 38 = 0
For a quadratic equation: ax² + bx + c
a = 1 , b = -4, c = -38
We apply almighty formula to find the values of x
[tex]x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}[/tex][tex]\begin{gathered} x\text{ = }\frac{-(-4)\pm\sqrt[]{(-4)^2-4(1)(-38)}}{2(1)} \\ x\text{ =}\frac{4\pm\sqrt[]{16+152}}{2} \end{gathered}[/tex][tex]\begin{gathered} x\text{ =}\frac{4\pm\sqrt[]{168}}{2}=\frac{4\pm\sqrt[]{4\times42}}{2} \\ =\text{ }\frac{4\pm2\sqrt[]{42}}{2}=\frac{2(2\pm\sqrt[]{42)}}{2}=(2\pm\sqrt[]{42)} \\ x\text{ = 2 +}\sqrt[]{42\text{ }}\text{ or 2 -}\sqrt[]{42\text{ }} \end{gathered}[/tex]The correct option: x= 2+/- sqrt42 (option A)
