$$\lambda(n)=(-1)^{\Omega(n)}=\sum\limits_{d^2|n}\mu\left(\frac{n}{d}\right)\tag{1}$$

$$L(x)=\sum\limits_{n\le x}\lambda(n)=\sum\limits_{n^2\le x} M\left(\frac{x}{n}\right)\tag{2}$$

where

$$M(x)=\sum _{n\le x}\mu(n)\tag{3}$$