PLease show formulas and work! Want to be able to understand...Will up vote!

The demand for subassembly S is 120 units in week 7. Each unit of S requires 2 units of T and 1 unit of U. Each unit of T requires 2 units of V, 2 units of W, and 2 units of X. Finally, each unit of U requires 1 unit of Y and 3 units of Z. One firm manufactures all items. It takes 2 weeks to make S, 1 week to make T, 2 weeks to make U, 1 week to make V, 3 weeks to make W, 1 week to make X, 2 weeks to make Y, and 2 weeks to make Z. Click the icon to view the product structure and the time-phased product structure. In addition to 120 units of S, there is also a demand for 20 units of U, which is a component of S. The 20 units of U are needed for maintenance purposes. These units are needed in week 6. Modify the gross material requirements plan to reflect this change (type 0 if the input box is not used). Week Lead Time (weeks) Item 1 2 3 4 5 6 7 S Gross req Order release 2 More Info - The product structure. The time-phased product structure. V Level 0 S xek W T T2) x (1 1 Y U Z Enter your an 2 V(2) W(2) X(2) Y(1) Z(3) 5 6 7 Time in weeks 7 parts remainin