Answer:
[tex]\huge\boxed{y=\sqrt{\dfrac{x-10}{2}}\ \text{for}\ x\geq10}[/tex]
Step-by-step explanation:
[tex]y=5x^2+10\\\\\text{exchange x to y and vice versa}\\\\x=5y^2+10\qquad|\text{subtract 10 from both sides}\\\\x-10=5y^2\qquad|\text{divide both sides by 5}\\\\\dfrac{x-10}{5}=y^2\\\\y^2=\dfrac{x-10}{5}\to y=\sqrt{\dfrac{x-10}{2}}[/tex]