The students would show no regard for the money being spent because it is not their money
We will use substitution to solve this system of linear equations, as the first equation has x and y with no coefficients, which makes it easier to find one in terms of the other. We can then substitute that value in the other equation and find the values of x and y.
x = y + 5 ---> equation 1
3x + 2y = 5 ---> equation 2
From equation 1, we get the value of x as y + 5. Using the substitution method, we can find the value of y by substituting (y+5) for x in the 2nd equation.
3(y+5) + 2y = 5
3y + 15 + 2y = 5
5y = 5 - 15
5y = -10
y = -2
Subsituting this value of y in (y+5), we can find x.
x = y + 5
x = -2 + 5
x = 3
Therefore, x = 3 and y = -2.
I will also solve this using elimination method.
Let us multiply equation 1 by 2, so that we get 2y in both equations.
2x = 2y + 10
3x + 2y = 5
Let us add both the equations.
2x + 3x + 2y = 5 + 2y + 10
5x = 15 + 2y - 2y
5x = 15
x = 3
Substituting this value of x in equation 1, we get
x = y + 5
3 = y + 5
y = 3 - 5
y = -2
Therefore, x = 3 and y = -2.
Answer:
68% of these phones last 3.87 years.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:
In which 
is the decay parameter.
The probability that x is lower or equal to a is given by:
Which has the following solution:
The probability of finding a value higher than x is:
The average lifetime of a certain new cell phone is 3.4 years.
This means that 
So
68% of these phones last how long (in years)?
This is x for which:
Then
68% of these phones last 3.87 years.
Answer:
B) 
Step-by-step explanation:
We want to simplify ![\sqrt[3]{-125n^{12}}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B-125n%5E%7B12%7D%7D)
![\sqrt[3]{-125n^{12}} = \sqrt[3]{-1 * - 1 * -1 * 5 * 5 * 5 * n^4 * n^4 * n^4} \\\\= \sqrt[3]{(-1)^3 * 5^3 * (n^4)^3}\\\\= -1 * 5 * n^4\\\\= -5n^4](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B-125n%5E%7B12%7D%7D%20%3D%20%5Csqrt%5B3%5D%7B-1%20%2A%20-%201%20%2A%20-1%20%2A%205%20%2A%205%20%2A%205%20%2A%20n%5E4%20%2A%20n%5E4%20%2A%20n%5E4%7D%20%5C%5C%5C%5C%3D%20%5Csqrt%5B3%5D%7B%28-1%29%5E3%20%2A%205%5E3%20%2A%20%28n%5E4%29%5E3%7D%5C%5C%5C%5C%3D%20-1%20%2A%205%20%2A%20n%5E4%5C%5C%5C%5C%3D%20-5n%5E4)
The answer is
f(x) = -5x^2 - x + 20;
f(3) = -5*3^2 - 3 + 20 = -5*9 - 3 + 20 = -45 - 3 + 20 = -28;
