Can you explain and solve the 13.1

13.1 What is the advantage of immediate addressing? 13.2 What are the limitations of direct addressing. 13.11 What are the advantages and disadvantages of using a variable-length instruction format? Problems 13.1. Given the following memory values and alone-address machine with an accumulator, what values do the following instructions load into the accumulator? Word 3 contains 15. Word 12 contains 18 . Word 15 contains 24 Word 18 contains 36 a. LOAD IMMEDIATE 3 b. LOAD DIRECT 3 c. LOAD INDIRECT 3 d. LOAD IMMEDIATE 15 e. LOAD INDIRECT 12 f. LOAD DIRECT 18