~ Simplifying
-4x + -4 = -7(x + 4)
~ Reorder the terms:
-4 + -4x = -7(x + 4)
~ Reorder the terms:
-4 + -4x = -7(4 + x)
-4 + -4x = (4 * -7 + x * -7)
-4 + -4x = (-28 + -7x)
~ Solving
-4 + -4x = -28 + -7x
~ Solving for variable 'x'.
~ Move all terms containing x to the left, all other terms to the right.
~ Add '7x' to each side of the equation.
-4 + -4x + 7x = -28 + -7x + 7x
~ Combine like terms: -4x + 7x = 3x
-4 + 3x = -28 + -7x + 7x
~ Combine like terms: -7x + 7x = 0
-4 + 3x = -28 + 0
-4 + 3x = -28
~ Add '4' to each side of the equation.
-4 + 4 + 3x = -28 + 4
~ Combine like terms: -4 + 4 = 0
0 + 3x = -28 + 4
3x = -28 + 4
~ Combine like terms: -28 + 4 = -24
3x = -24
~ Divide each side by '3'.
x = -8
~ Simplifying
x = -8
Answer:
ΔT = ΔT0 e^-K T
As I understand Newton's Law of Cooling
ΔT at any time is the difference between the temperature and the surroundings
Originally ΔT0 = 95 - 22 difference between 95 and room temperature
65 - 22 = 33 = 73 e^-KT where t is time to cool to 65 deg
ln (33/73) = -KT K = .794 / 5 = .159 where 5 is time to cool to 65 deg
40 - 22 = 73 e^-.159 T where t is time to cool to 40 deg
18 = 73 e^-.159 T
ln (18 / 73) = -.159 T
T = 8.8 min
It would take 8.8 min for the object to cool to 40 deg C
Suppose the object cooled from 95 to 90 deg, then
ln 68 / 73 = -.159 T and T = .45 min
Answer:
Whole numbers are also integers. There are other integers which are the opposites of the whole numbers (−1, −2, −3, ...). These negative numbers lie to the left of 0 on the number line. Integers are the whole numbers and their opposites.
By adding all the numbers and dividing by 7 ( the amount of numbers) you know that the answer will be about 166.3
-5 i think.....................
