The answer is 39 and I know because I took the test and got it right
We have to factor becasue
area=legnth times width
area=4x^2+28x+49
area=(2x+7)(2x+7)
area=(2x+7)^2
legnth =width
we arent' given area so we can't solve
but, , since it is a squaer room, legnth=width so √area=legnth=width
Answer:
B
Step-by-step explanation:
Because you have to solve for the variable, making it algebraic.
The equation (1) is divided by 2 to create new equivalent system of equations.
Step-by-step explanation:
The given systems of equations are:

Considering 8y instead of 8 in eq(1)
We need to identify what action was completed to create this new equivalent system of equations? 
Comparing given equations we came to know that equation(1) is divided by 2 to get the new equation i.e

While second equation is same as given.
So, The equation (1) is divided by 2 to create new equivalent system of equations.
Keywords:System of Equation
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The function that represents surviving people are X = 2m - d
Given that there are m married couples and d of the 2m of these couples have died, the total people that remain is expressed as:
Total people remaining = Total married couple - those that died
Total married couple = 2m
Total people that died = d
Taking the difference to get the remaining people;
Total people remaining = 2m - d
Hence the function that represents surviving people are X = 2m - d
Learn more on difference here: brainly.com/question/2605546