Answer: 
Step-by-step explanation:
The rate of change is a measure in which one variable is modified in relation to another. In this case we have the variables:
Temperature in 
Time in 
Now, to calculate the rate of change, we have to divide one variable by the other. In this case the change in temperature
divided by the time variation
.
Hence, assuming the ambient temperature of the glass is
and the elapsed time
we have:

I suppose we have to find the lengh of the sides.
Area = lenght × width
288 = (3x) × (2x+10)
288 = 3x (2x+10)
288 = 6x + 30x
288 = 36x
288/36 = x
8 = x
therefore the sides are
3x = 3×8 = 24 inches
2x+10 = 2×8 + 10 = 16 +10 = 26 inches
Answer:
-17 z - 6 y - 7 x + -18
Step-by-step explanation:
Simplify the following:
x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20
Hint: | Group like terms in x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20.
Grouping like terms, x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20 = (-7 z - 10 z) + (6 y - 12 y) + (x - 8 x) + (2 - 20):
(-7 z - 10 z) + (6 y - 12 y) + (x - 8 x) + (2 - 20)
Hint: | Combine like terms in -7 z - 10 z.
-7 z - 10 z = -17 z:
-17 z + (6 y - 12 y) + (x - 8 x) + (2 - 20)
Hint: | Combine like terms in 6 y - 12 y.
6 y - 12 y = -6 y:
-17 z + -6 y + (x - 8 x) + (2 - 20)
Hint: | Combine like terms in x - 8 x.
x - 8 x = -7 x:
-17 z - 6 y + -7 x + (2 - 20)
Hint: | Evaluate 2 - 20.
2 - 20 = -18:
Answer: -17 z - 6 y - 7 x + -18