Leysa {l}{A=pir^2}{a=r^2}{b=a}{c=b}{text{Solvefor}dtext{where}}{d=c}

$$\left. \begin{array} { l } { A = \pi r ^ {2} }\\ { a = r ^ {2} }\\ { b = a }\\ { c = b }\\ { \text{Solve for } d \text{ where} } \\ { d = c } \end{array} \right.$$

Leystu fyrir A, r, a, b, c, d

$$r=-\sqrt{d}\text{, }A=\pi d\text{, }a=d\text{, }b=d\text{, }c=d\text{, }d\geq 0$$

$$r=\sqrt{d}\text{, }A=\pi d\text{, }a=d\text{, }b=d\text{, }c=d\text{, }d\geq 0$$