if it were getting warmer, the negative number would get closer to 0, not farther away.
For example, at 9am the temperature was -4 degrees and by noon it was -1 degrees. It has gotten 3 degrees warmer.
If your looking for hourly they sold a total of 12 tacos per hour.
If your looking for daily they sold a total of 288 tacos per day.
Assuming that the two investments are X & Y
X + Y = 6300
X = 6300 - Y (1)
9/100X + 4/100 Y = 372 (2)
replacing X from (1) into (2)
9/100(6300-Y) + 4/100 Y = 372
567 - 9/100Y +4/100Y = 372
(-9+4)/100Y = 372 - 567
5/100Y = -195
Y = 100*195/5 = 3900
From (1) we can get X
X = 6300 - 3900 = 2400
I hope this is helpful