Question

Solve the quadratic equation by quadratic formula .$9d^2-12d=-4$

Short answer

The required result is$d=\frac{2}{3}$

Step-by-step solution

 Given Information 

The given equation is$9d^2-12d=-4$

Write the quadratic equation in standard form and identify .a ,b,c

The quadratic equation in standard form

$9d^2-12d+4=0$

So ,

$a=9,b=-12,c=4$

Substitute the values in quadratic formula. 

$$\begin{gathered} x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} \\ d=\frac{-\left(-12\right)\pm \sqrt{{\left(-12\right)}^2-4\left(9\right)\left(4\right)}}{2\left(9\right)} \\ d=\frac{12\pm \sqrt{144-144}}{18} \\ d=\frac{12\pm 0}{18} \\ d=\frac{12}{18} \\ d=\frac{2}{3} \end{gathered}$$