What is the difference between the product of 12 and 8 and the sum of 12 and 8

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Ametal rod needs to be 9 feet and 5.5 inches in length. the sections of the poles being used are each 1 foot and 10.5 inches long. how many 1ft 10.5in sections would be needed to complete the 9ft 5.5in metal rod? and how many inches of material will be left?

What number line represents the solution set for the inequality -1/2 greater than or equal to 4