Answer:

Step-by-step explanation:
If we had 2 independent samples with population variances unknown and equal and we want to compare the population mean between the both groups, the test statistic will be:

Where 
So, the t-student has
degrees of freedom
Where
and
are the means of the groups,
and
are the size of the samples and
and
are the sample variances.
The answer could be x = -y
The function is degree 2 ( because of the x^2) so it is non-linear.
Answer:
There are no solutions to the system because the equations represent parallel lines.
Step-by-step explanation:
The given system is solved using the linear combination method.
By solving we had the result 0=-12.
We need to interpret this result in terms number of solutions.
Since 0 is never equal to -12, it means the system has no solution.
This means that the lines do not intersect
Answer:
Dom = R - {-4}
Range = R - {0}
Step-by-step explanation: