Answer: 2x(3x−1)(x+2)
Step-by-step explanation:
Answer:
- c = -4.5
- z = 20
- x = -12
- a = -4/7
Step-by-step explanation:
A way to do this that will always work is ...
- eliminate parenthses and collect terms
- subtract any constants from the left side
- subtract any variable terms from the right side
- divide by the coefficient of the variable
1.
- 8c -11 -6c = -2
- 2c -11 = -2
- 2c = 9
- c = 4.5
2.
- 3z +4 -2z -9 = 15
- z -5 = 15
- z = 20
3.
- 12 -4x +18 = 36 +4x +18 -6x
- 30 -4x = 54 -2x
- -4x = 24 -2x
- -2x = 24
- x = -12
4.
- 36a -9a -5 = 6a -17
- 27a -5 = 6a -17
- 27a = 6a -12
- 21a = -12
- a = -12/21 = -4/7
Answer:
H0: μ = 5 versus Ha: μ < 5.
Step-by-step explanation:
Given:
μ = true average radioactivity level(picocuries per liter)
5 pCi/L = dividing line between safe and unsafe water
The recommended test here is to test the null hypothesis, H0: μ = 5 against the alternative hypothesis Ha: μ < 5.
A type I error, is an error where the null hypothesis, H0 is rejected when it is true.
We know type I error can be controlled, so safer option which is to test H0: μ = 5 vs Ha: μ < 5 is recommended.
Here, a type I error involves declaring the water is safe when it is not safe. A test which ensures that this error is highly unlikely is desirable because this is a very serious error. We prefer that the most serious error be a type I error because it can be explicitly controlled.
