A 20% acid solution is mixed with a 70% acid solution to get 100 liters of a 50% solution. If x= the amount of 20% solution and y = the amount of 70% solution, which of the following expressions equals 500?
0.2x+0.7y
20x + 70y
2x+7y

answer:

c 60% on edg

the photograph is photographer and- in the process- ourselves.

step-by-step explanation:

the functions have the same rate of change i think. i narrowed it down to this answer and "the rate of change of tour 1 is greater" but i got it wrong using that answer so im assuming its the answer above. (this is a question i also answered from the iready site if anyone needs a reference)