Can you also explain, i need this done very fast

15) a) -3 and -4

-3(-4) = 12 (two negative numbers multiplied or divided together = positive answer)

      b) -5 and 6
6(-5) = -30 (one negative number and one positive number multiplied together = negative answer)
-5 + 6 = 1

16) 2.4 kg, 0.7 kg
c) a loss of 15kg should be your answer, because the loss has a larger number proportion than the gained

hope this helps

The amount used= 13.04- 1.9 = 11.14