The multivariate demand function below will be needed for questions 12-18. Setting: Grapple, Inc. is a leading seller of laptop personal computers. However, they want to become a leading tablet seller, too. Your marketing department, aided by your economics staff, has estimated a function to help you in the quest for market leader in tablets. The variables are defined after the function. Q, =10000 - 25P + 20P + 30P, -15P -35P -10Pm + 0.05A +0.03A - 25C +0.1Y Q: = the number of Grapple tablet computers demanded per week. P = the price of each new Grapple tablet (in $)- Ph = the price of each Hewpaq tablet (in $). Pr = the price of each Ronova tablet. Pay = the price to equip a tablet with Holographic digital video (in $, this is an upgrade option that enables three dimensional graphics on a tablet. Two dimensional graphics is standard equipment). Pac = the price of various screen sizes (in $, a 8 inch is standard, but upgrade options are 10 inch extra sharp, 12 inch, 12 inch extra sharp, Each also has a touch-screen option. The upgrades get progressively more expensive as the size and capability increases). Pmm = the price of memory chip upgrades (in $). More 2 Gigabyte (Gb) chips can be added. Of course each added 2 Gb chip costs more. One 2 Gb chip is standard. Y = average annual disposable income of a typical tablet purchaser (in $). Ag = average age of a tablet purchaser (in years). A = average annual Grapple advertising expenditure (in $). C = number of computer systems the average tablet purchaser already owns. 12. If all variables remain unchanged except the price of a Grapple tablet (P ), which increases by $50, then the quantity demanded of tablets will: 13. If all variables remain unchanged except the price of Ronova (Pr) tablets, which increases by $50, then the demand for Grapple tablets will