Question 9A value of $x$ satisfying the equation $x^2+b^2=(a-x)^2$ is:$\dfrac{b^2+a^2}{2a}$$\dfrac{b^2-a^2}{2a}$$\dfrac{a^2-b^2}{2a}$$\dfrac{a-b}{2}$$\dfrac{a^2-b^2}{2}$