The last graph represents a system with no solutions. The solution to a system of equations is the point at which both lines intersect. Because the equations in the last graph don't intersect and are parallel, it has no solutions. Hope this helps :))
−5 < a − 4 < 2
+4 +4
-1 < a < 6
Answer is B. The second one
Answer:

C 8.0
Step-by-step explanation:
Assuming the linear model y=mx+b where m is the slope and b the intercept.
For this case the slope with the following formula:
Where:

After the calculations we see that m=3 and b=2 from the info given by the linear model.
For this case we have the equation obtained by least squares given by:

Where 2 represent the intercept and 3 the slope. We are interested on the best predicted value of y when x=2.
If we see our linear model we have the equation in terms of y and x. So we can replace directly the value of x=2 into the equation and see what we got:

Here the answer is http://prntscr.com/amkn6t thank you
If the girls were counted as negative and the boys positive. It would be -2 couples