[tex]x\geq0\\\\b+t\sqrt{x}=a\qquad|\text{subtract b from both sides}\\\\t\sqrt{x}=a-b\qquad|\text{divide both sides by }\ t\neq0\\\\\sqrt{x}=\dfrac{a-b}{t}\qquad|\text{square of both sides}\\\\(\sqrt{x})^2=\left(\dfrac{a-b}{t}\right)^2\\\\\boxed{x=\left(\dfrac{a-b}{t}\right)^2}[/tex]
