Answer:
The variable "a number" stands for 9.
Step-by-step explanation:
Rewrite the problem as 2 * (6 + x) = 30
Divide 30 into 2. 30/2 = 15
That means that the variable that is added to 6 must make the number 15.
15 - 6 = 9
The variable x is 9 so the equation would be:
2 * (6 + 9) = 30

all you have to do next is add all of them in one equation and equate them to 18
when you find x, replace in each expression to get your answers
Answer:
For this case we want to test if life expectancy in country 1 is more than 10 years lower than in country 2, (alternatibe hypothesis), so then the system of hypothesis are:
Null hypothesis: 
Alternative hypothesis:
Or equivalently:
Null hypothesis: 
Alternative hypothesis:
Step-by-step explanation:
Previous concepts
A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".
The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".
The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".
Solution to the problem
For this case we want to test if life expectancy in country 1 is more than 10 years lower than in country 2, (alternatibe hypothesis), so then the system of hypothesis are:
Null hypothesis: 
Alternative hypothesis:
Or equivalently:
Null hypothesis: 
Alternative hypothesis:
Answer:
15 weeks
Step-by-step explanation:
850-250= 600
40*15= 600
210 is 11010010 in binary form