Answer:
x= -2/3y-4
Step-by-step explanation:
3x+2y=-12
3x+2y-2y= -2y-12
3x=-2y-12
3x/3= -2y/3-12/3
x= -2/3y-4
Answer:
a.1.90 years
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
In this question:

So

So the correct answer is:
a.1.90 years
Answer:
c) 3x - 45 = 10
Step-by-step explanation:

Cross multiply,
3*(x - 15) = 2*5
3*x - 3*15 = 10
3x - 45 = 10
Answer: a = 4/3
Step-by-step explanation:
1. a/4 − 5/6= −1/2 convert -1/2 to -3/6
2. a/4 = 5/6 - 3/6 = 2/6 = 1/3
3. a = 4*2/6 = 4*1/3
4. a = 4/3