The rate of change is +2
as an ordered pair it would be (1,-3),(2,-1)(3,1),(4,3)
Every 56 seconds, the radioactive substance is divided in half.
224 / 56 = 4
We need to cut the substance in half 4 times.
896 / 2 = 448
448 / 2 = 224
224 / 2 = 112
112 / 2 = 56
After 224 seconds, there will be 56 grams of the radioactive substance left over
5x - 3y = -11 (×2)
2x - 6y = -14 (x5)
10x - 6y = -22
10x - 30y = -70
---------------------- -
24y = 48
y = 2