Expand $(y−3)^2$.

Set the equation equal to $0$.

Factor and use the Zero Product Property or use the Quadratic Formula to solve.

$y=4\pm i\sqrt(3)$

This equation has an absolute value, so you will need to write two equations to solve it.

$y−3=2y−10$ or $y−3=−(2y−10)$

$y=7\text{ or }y=\frac{13}{3}$

Check both solutions in the original equation.
Do they both solve the equation?