Answer:
(1,1) x=1 y=1
Step-by-step explanation:
Let's identify what we are looking for in terms of variables. Sandwiches are s and coffee is c. Casey buys 3 sandwiches, which is represented then by 3s, and 5 cups of coffee, which is represented by 5c. Those all put together on one bill comes to 26. So Casey's equation for his purchases is 3s + 5c = 26. Eric buys 4 sandwiches, 4s, and 2 cups of coffee, 2c, and his total purchase was 23. Eric's equation for his purchases then is 4s + 2c = 23. In order to solve for c, the cost of a cup of coffee, we need to multiply both of those bolded equations by some factor to eliminate the s's. The coefficients on the s terms are 4 and 3. 4 and 3 both go into 12 evenly, so we will multiply the first bolded equation by 4 and the second one by -3 so the s terms cancel out. 4[3s + 5c = 26] means that 12s + 20c = 104. Multiplying the second bolded equation by -3: -3[4s + 2c = 23] means that -12s - 6c = -69. The s terms cancel because 12s - 12s = 0s. We are left with a system of equations that just contain one unknown now, which is c, what we are looking to solve for. 20c = 104 and -6c = -69. Adding those together by the method of elimination (which is what we've been doing all this time), 14c = 35. That means that c = 2.5 and a cup of coffee is $2.50. There you go!
Answer:
Step-by-step explanation:
For a given function f(x), we define the domain as the set of the possible inputs of the function and the range as the set of the outputs of the function.
We will see that both domain and range are the set of all real numbers.
D = (-∞, ∞)
R = (-∞, ∞)
Here we have the function:
The first thing we need to do is find the domain.
We start by assuming that the domain is the set of all real numbers and then we try to find some given values of x that cause some undefined operation, and then we remove these values of x from the domain.
Where this would be something like a zero in the denominator or something like that. We also could have specific restrictions to the domain that are applied in some specific cases (for example if x represents a length we should remove the negative values from the domain).
Here we can see that we do not have any indetermination, thus the domain is the set of all real numbers.
Now to study the range we need to see the general function, we can see that as x tends to negative infinity y will also tend to negative infinity, while when x tends to infinity y will also tend to infinity.
Then the range will also be the set of all real numbers.
8 hours and 41 mins per day!
(About 9 hours)
Hoped I helped!
Answer:
A certain amount I do not know
