how did u derive the outputs for F & H from truth table?

Use the Karnaugh Map (the 2 tables at the top right corner), AB\CD, then you fill in the table with the outputs of F and H respectively for different combinations of ABCD (as shown in the truth table). From the map, group as many 1s as possible, in groups of 2 or 4 or 8 or 16 etc (powers of 2 except 1). Then you find the similarities in each group, e.g. A is always 0, means not A). Then you combine the results of each group using + sign, this result is the output of F or H respectively. You can read up on the Karnaugh Map to get more detailed explanations.

i see thank you so much i get it now