Answer:
k = - 6.6667
Step-by-step explanation:
this is quite very simple to begin. I would encourage you take other practice questions similar to help with understanding it.
let us begin.
Given that ;
dT/dt = k ( Tm - T) where Tm is the temp of the medium
dT/dt = 5 degrees Celsius per minute when T = 70
so we have that, 5 = k ( 25 - 70)
remember to convert 5 degree celsius per minute to seconds
we have that;
5*60(sec) = k ( 25 - 70)
k = 5*60 / ( 25 - 70)
k = - 6.6667
note K is negative because we consider it for cooling process (temp decreasing).
cheers i hope this helps!!!
Answer:
e) 1.7%
Step-by-step explanation:
1 / 58 = 0.017
0.017 * 100 = 1.7
![- 5x+2y=9 \\ y=7x](https://tex.z-dn.net/?f=%20-%205x%2B2y%3D9%20%5C%5C%20%3C%2Fp%3E%3Cp%3Ey%3D7x)
We know that y=7x, so we just need tu put it into the 1st equation
![- 5x + 2 \times 7x = 9 \\ - 5x + 14x = 9 \\ 9x = 9 | \div 9 \\ 9x \div 9 = 9 \div 9 \\ x = 1](https://tex.z-dn.net/?f=%20-%205x%20%2B%202%20%5Ctimes%207x%20%3D%209%20%5C%5C%20%20-%205x%20%2B%2014x%20%3D%209%20%5C%5C%209x%20%3D%209%20%7C%20%5Cdiv%209%20%5C%5C%209x%20%5Cdiv%209%20%3D%209%20%5Cdiv%209%20%5C%5C%20x%20%3D%201)
So we found x. Now we can find y
![y = 7 \times 1 \\ y = 7](https://tex.z-dn.net/?f=y%20%3D%207%20%5Ctimes%201%20%5C%5C%20y%20%3D%207)
Answer:
x=1, y=7; or (1;7)
7-2/3x<x-8
add 2/3x to both sides
7<5/3x-8
add 8 to both sides
15<5/3x
times 3 both sides
45<5x
divide both sides by 5
9<x
Answer 433=20.81
Step-by-step explanation: