Answer:
![x^2 - 8x + 7 = 0](https://tex.z-dn.net/?f=x%5E2%20-%208x%20%2B%207%20%3D%200)
Step-by-step explanation:
Let the boy's present age be x.
Let his dad's present name be y.
Last year, his dad was 8 times as old as him. Subtract one year from each their ages and multiply the son's age by 8:
(y - 1) = 8(x - 1) ______ (1)
Now, his dad's age is the square of his age:
y =
_________(2)
From (1):
y = 8x - 8 + 1
y = 8x -7
Put this in (2):
![8x - 7 = x^2\\\\=> x^2 - 8x + 7 = 0](https://tex.z-dn.net/?f=8x%20-%207%20%3D%20x%5E2%5C%5C%5C%5C%3D%3E%20x%5E2%20-%208x%20%2B%207%20%3D%200)
This problem has been represented in the form of a quadratic equation.
Max has 21 and Mene has 43 the equation would be 21 + 43 = 64
they have 64 all together
The answer is C I read the passage took the test and did good.
Answer:
![c = 100\,\frac{J}{kg\cdot ^{\circ}C}](https://tex.z-dn.net/?f=c%20%3D%20100%5C%2C%5Cfrac%7BJ%7D%7Bkg%5Ccdot%20%5E%7B%5Ccirc%7DC%7D)
Step-by-step explanation:
According to the First Law of Thermodynamics, the heat received by the metal cylinder is equal to the change in the internal energy. That is:
![Q = \Delta U](https://tex.z-dn.net/?f=Q%20%3D%20%5CDelta%20U)
![Q = m \cdot c \cdot \Delta T](https://tex.z-dn.net/?f=Q%20%3D%20m%20%5Ccdot%20c%20%5Ccdot%20%5CDelta%20T)
The specific heat is clear in the previous expression and finally computed:
![c = \frac{Q}{m\cdot \Delta T}](https://tex.z-dn.net/?f=c%20%3D%20%5Cfrac%7BQ%7D%7Bm%5Ccdot%20%5CDelta%20T%7D)
![c = \frac{1600\,J}{(2\,kg)\cdot (13^{\circ}C-5^{\circ}C)}](https://tex.z-dn.net/?f=c%20%3D%20%5Cfrac%7B1600%5C%2CJ%7D%7B%282%5C%2Ckg%29%5Ccdot%20%2813%5E%7B%5Ccirc%7DC-5%5E%7B%5Ccirc%7DC%29%7D)
![c = 100\,\frac{J}{kg\cdot ^{\circ}C}](https://tex.z-dn.net/?f=c%20%3D%20100%5C%2C%5Cfrac%7BJ%7D%7Bkg%5Ccdot%20%5E%7B%5Ccirc%7DC%7D)
Answer:
68 square centimeters
Step-by-step explanation:
All u have to do is add them all together.