Let y be the temperature
Let m be the rate of temperature drop in degrees per hour
Let x be the number of hours elapsed since 8PM
The initial temperature (at x = 0) is 0
y = mx
Four hours from 8 PM, the temperature was -16.8 degrees
-16.8 = m(4)
m = -4.2 degrees per hour
At 9PM, one hour will have elapsed.
y = -4.2(1)
y = -4.2 degrees
Y intercept is (0,-12), the x-intercept is (4,0)
20 seconds
i feel like that is right
Answer:
C, D
Step-by-step explanation:
This equation can be solved any of several ways. One that doesn't require much thought is using the quadratic formula.
For ax² +bx +c = 0, the solutions are ...

In the given equation, a=2, b=11, c=5, so this becomes ...

The solutions are ...
C. x = -5
D. x = -1/2
_____
My personal favorite is using a graphing calculator. The solutions are the x-intercepts of the expression on the left. That is, where its value is zero, as the equation says.
Answer:=
Solution: -2<c<3
Interval Notation: (-2,3)
Step-by-step explanation:
-3<5c+7<22
-3<5c+7 : c>-2
5c+7<22 : c<3
combine the intervals
c>-2 and c<3
-2<c<3