## $x/4 = y/x = 7/y$

Could someone please explain to me what’s wrong here?

$$\cfrac{x}{4} = \cfrac{y}{x} = \cfrac{7}{y}$$

So $$\cfrac{x^2}{4} = y \ \ \ \ \ \ \ \text{and} \ \ \ \ \ \ \ y = \sqrt{7x}$$

Hence $$\cfrac{x^2}{4} =\sqrt{7x}$$

With a solution of $$x = 2.57$$

But $$\cfrac{2.57^2}{4} \neq \sqrt{7 (2.57)}$$