Which of the following points is a solution to the system of equations shown?
x + y = -5 and 4x + y = 1

(2,-7)
(7,12)
(4, -5)

First Option (2,-7)

Step-by-step explanation:

We have a system of equations formed by the following equations:

To answer this question we must solve the system of equations. There are several ways to solve it. The easiest way to solve it for this case is to multiply the second equation by -1 and then add it to the first equation.

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Now substitute x = 2 in any of the system equations and solve for y.

Therefore the solution of the system is the point: (2, -7)

add the table and i will answer correctly

step-by-step explanation:

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.