Concept: Isolate the square root, then square both sides to solve for x.Explanation:Start with the given equation:y=3N2x2+mMultiply both sides by 3N:3Ny=2x2+mDivide both sides by 2:23Ny=x2+mSquare both sides to eliminate the square root:(23Ny)2=x2+m49N2y2=x2+mSubtract m from both sides:x2=49N2y2−mx2=49N2y2−4mTake the positive square root:x=29N2y2−4mAnswer:x=29y2N2−4m, which is option B.