A block of mass $m$ is at natural length initially.It is attached to two springs having spring constant $k1$ and $k2$. It is attached in such a way that when one elongates ,the other compresses.Using work energy theorem , I need to find the velocity of the block at half the amplitude of release of the block. Spring stores energy as $0.5kx^2$. The sign is decided if the force by spring is opposing displacement($-ve$) or along displacement($+ve$). Is this concept also applied in Work-energy equation where initial system energy is equal to final energy system?