Answer:
19.32
Step-by-step explanation:
To find the missing number, we need to solve for the total of the left side of the equation.
Total = 8.4(1.5 + 2.3)
Total = 8.4(3.8)
Total = 31.92
Now we subtract the total to the only value on the right side.
Missing number = 31.9-12.6
Missing number = 19.32
8.4(1.5+2.3) = 12.6 + 19.32
C = 25 because the amount of broth doesn't change
d = 60 because you add the total before to the new total
Answer:
![t= \frac{125}{38} s](https://tex.z-dn.net/?f=t%3D%20%5Cfrac%7B125%7D%7B38%7D%20s)
Step-by-step explanation:
We are given the temperature inside the machine from startup until 10 seconds later, the formula is:
![h(t)= 42 \cdot t +1 - 4\cdot t +2 (degrees \, C)](https://tex.z-dn.net/?f=h%28t%29%3D%2042%20%5Ccdot%20t%20%2B1%20-%204%5Ccdot%20t%20%2B2%20%20%28degrees%20%5C%2C%20C%29)
We want to know at what time t the temperature inside the machine will be equal to 128 °C.
So we set:
![h(t)=128](https://tex.z-dn.net/?f=h%28t%29%3D128)
![42\cdot t+1-4\cdot t+2=128](https://tex.z-dn.net/?f=42%5Ccdot%20t%2B1-4%5Ccdot%20t%2B2%3D128)
Now, we rearrange the equation to keep terms with t on the left hand side and terms without t on the right hand side
![42\cdot t-4\cdot t=128-1-2](https://tex.z-dn.net/?f=42%5Ccdot%20t-4%5Ccdot%20t%3D128-1-2)
and we simplify:
![(42-4)\cdot t= 128-2-1= 125](https://tex.z-dn.net/?f=%2842-4%29%5Ccdot%20t%3D%20128-2-1%3D%20125)
![38 \cdot t = 125](https://tex.z-dn.net/?f=38%20%5Ccdot%20t%20%3D%20125)
now it's easy to solve for t:
![t=\frac{125}{38}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B125%7D%7B38%7D)
And thus we arrive to the solution.
The answer is 20, because it goes up every time.