(finding the slope on a table) its really simple but i forget the steps in doing slope ^the question is in the picture above

Can someone, me with this.i really need with this

Has a picture and need within 5 min

Anut store normally sells cashews for? $4.00 per pound and peanuts for? $1.50 per pound. but at the end of the month the peanuts had not sold? well, so, in order to sell 40 pounds of? peanuts, the manager decided to mix the 40 pounds of peanuts with some cashews and sell the mixture for $2.00 per pound. how many pounds of cashews should be mixed with the peanuts to ensure no change in the? profit?