Asalt solution having a concentration of cin = 2 pounds per gallon flows at a rate of ˙vin = 10 gallons per minute into a 125-gallon capacity tank, while the well-stirred solution is being pumped out at a rate of ˙vout = 5 gallons per minute. if the tank initially contained 500 pounds of salt dissolved in 50 gallons of water. when the amount of salt in the tank reach minimum?

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.