F2-?

The image depicts a lever in equilibrium. The principle of moments states that for a lever to be balanced, the sum of the clockwise moments must equal the sum of the counter-clockwise moments. In this case, the moment due to F1 is $$M_1 = F_1 \times l_1$$, and the moment due to F2 is $$M_2 = F_2 \times l_2$$. Assuming the lever is balanced, $$M_1 = M_2$$. However, the lengths $$l_1$$ and $$l_2$$ are not explicitly given in relation to each other, nor is the position of the fulcrum relative to the forces. Without further information or a clear diagram indicating the distances from the fulcrum, it is impossible to calculate F2.