In Mathematics, having a sound foundation/base is very essential to help us navigate through tough concepts in higher classes.
Like, solving (x-4)^2 < 9; x>0.
To solve this, knowing how to solve solve squares is basic. Like, finding the sqaure of 9, 16 should be known.
Then, knowing how to solve x^2 = 9 is needed.
Then, learning to solve (x-4)^2 = 9 is required. Then, apply that knowledge to solve (x-4)^2 < 9 and see whether the solution meets the given condition or not.