Question

The area of a circle is given by the expression (22/7)×x^2+6×(22/7)×x+9×(22/7). Find the radius of the circle

Answer 1

Answer:

I am writing π at place of 22/7 , and assume radius is r .

$\pi \: {x}^{2} + 6\pi \: x + 9\pi = \pi {r}^{2} \\ \pi{r}^{2} = \pi( {x}^{2} + 6x + 9) \\ {r}^{2} = {x}^{2} + 6x + 9 \\ {r}^{2} = (x + 3) {}^{2} \\ r = \pm(x + 3)$