The solution to this is 5√(11)/11
On day no 9, because to increase her mileage by 4 to reach 8 it will take her 4/0.5=8 days plus day 1 where she ran just 4 miles.
hello!
so the answer that you put there is actually wrong and i'll tell you why and how to do it
so since you are adding the two:
-8x + 9x = x (so you got this part right)
-12 + 4 = -8 (this is where you got it wrong, -12 added 4 goes up in value to -8)
so the final answer is x - 8
i hope this helped and have a nice day!
