1. “ at this age , my baby will not cry because we are leaving.”
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!
The answer that you are looking for is 215
Answer:
-6
Step-by-step explanation:
7x + 9 = 5x -3
-5x -5x
2x+9=-3
-9 -9
2x=-12
divide by 2
x = -6
Using a t-distribution calculator, it is found that the critical value of the test statistic t is
.
<h3>How to find the critical value of a t-test?</h3>
- The critical value is found using a calculator.
The inputs are:
- The amount of degrees of freedom, which is one less than the sample size.
In this problem, we have a<u> lower(left-tailed) test, with 10 - 1 = 9 df and a level of significance of 0.1</u>, hence the critical value is
.
You can learn more about the t-distribution at brainly.com/question/26062194