60 hope this helps!!!!!!!!!!!!!!!
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:
EHRP, EHFG, EFPQ Does that make sense?
Answer:
G = 14 - 1.75(t)
Where G is the number of gallons of gas remaining;
14 represents the amount of gas in gallons in the full gas tank of the vehicle
t is the number of hours
Step-by-step explanation:
Here, we want to write an equation.
We are told that the car uses 1.75 gallons of gas every hour and after 4 hours 7 gallons were left
In the 4 hours, the amount of fuel used will be 1.75 * 4 = 7 gallons
So therefore since we have 7 gallons left, the amount of gallons in the full tank of the vehicle will be 7 + 7 = 14 gallons
Hence, the equation we want to write will be;
G = 14 - 1.75(t)
You can do substitution 2x-2=x^2 -x -6; isolate all terms on one side 0= x^2 -x-2x -6+2; combine like terms x^2 -3x -4=0; factor the quadratic (x-4)(x+1)=0; each term is zero x-4=0 so x=4 and x+1=0 so x=-1. Now, y=2•4-2=6 and y=2•(-1) -2= -4 ; solutions for the system are ( 4,6) and ( -1, -4)