The water temperature in the swimming pool
began at 79 degrees,
and it is rising 0.8
degrees each hour. If
the water temperature is
84 degrees, then how
many hours have passed?

7.3

step-by-step explanation:

81+30=111180 minus 111=691/2×19=9.569÷9.5=7.263157895~7.3

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.