I need some help understanding how to solve these problems, could I get some assistance?

7. [0/1 Points] DETAILS PREVIOUS ANSWERS Solve for X in the equation, where A = -4 1 2 - 5 2 1 and B = 20 2X = 2A - B X = X Need Help? Read It Watch It Submit Answer 8. [-/1 Points] DETAILS If possible, find AB. (If not possible, enter IMPOSSIBLE.) A = 0 2 - 5 6 14 7 -18 AB = State the dimension of the result. (If not possible, enter IMPOSSIBLE in both answer blanks.)11. [-/1 Points] DETAILS Evaluate the expression. Use the matrix capabilities of a graphing utility to verify your answer. ( [5 - 8 / + 10 - 1 ] + 1-7 7 ] ) Need Help? Read It Watch It 12. [-/1 Points] DETAILS Consider the following. X1 - X2 + 4X3 = 25 X1 + 3X2 -15 -6X2 + 5X3 = 58 (a) Write the system of linear equations as a matrix equation, AX = B. (b) Use Gauss-Jordan elimination on [A : B] to solve for the matrix X. X1 X = X2 X39. [-/1 Points] DETAILS Use the matrix capabilities of a graphing utility to find AB, if possible. (If not possible, enter IMPOSSIBLE.) 13 -15 2 11 12 A = 14 15 14 B = -2 11 9 -2 6 13 16 AB =13. [41 Points] DETAILS At a local store, the numbers of gallons of skim milk, 2% milk, and whole milk sold over the weekend are represented by A. Skim 2% Whole milk milk milk 39 68 51 Friday A = El] 83 76 Saturday 73 92 86 Sunday The selling prices per gallon and the prots per gallon for the three types of milk are represented by B. Selling price $3.45 $1.20 Skimmilk B: $3.65 $1.30 2%milk $3.85 $1.45 1.fiu'holemilk Prot (a) Compute AB. CID It Interpret the result. 0 The entries represent the total prot (in dollars). 0 The entries represent the total sales [in dollars) and the profit (in dollars} for milk on Friday, Saturday, and Sunday. 0 The entries represent the quantity of milk sold on Friday, Saturday, and Sunday. 0 The entries represent the selling price (in dollars) and total prot (in dollars} for milk over the entire weekend. 0 The entries represent the cost [in dollars) of producing skim milk, 2% milk, and whole milk on Friday, Saturday, and Sunday. (h) Find the store's total prot from milk sales for the weekend. $|:|