Which is the value of y in the system of equations 4x-5y=18 5x+y=58

Using systems of equations, we need to eliminate one variable to make it into a 1 variable equation either using elimination or substitution.

Equation 1: 4x - 5y = 18

Equation 2: 5x+y = 58

For equation 2, there is only one y which makes it easy to substitute. So subtract 5x from both sides of the equation to get

y = -5x+58

Then we know what y is in terms of x, so plug it into equation 1.

4x - 5(-5x+58) = 18

It is now an equation with only 1 variable, which we can solve.

Distribute the -5 to (-5x+58)

4x+25x-290 = 18

Combine like terms

29x-290 = 18

Add 290 to both sides

29x = 308

Divide both sides by 29 to isolate the x

x = 308/29 wow what an ugly number, but its alright

Plug in x to equation 2 to find what y is

5(308/29)+y = 58

1540/29+y = 58

Subtract 1540/29 from both sides

y = 142/29

The y value is 142/29

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.

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.