The cost C (in dollars) of making a square window with a side length of n feet is represented by C = 3.5 n ​2 A window costs $126. What is the length

C = 3.5n²

 

Plug in what you know.

126 = 3.5n²

 

Divide both sides by 3.5

126/3.5 = n²

36 = n²

 

Take the square root of both sides.

√(36) = n

6 feet = n

 

side length = 6 feet

A square window would have 4 equal sides

so 126 / 4 =31.5

Meaning each side othe square window would cost $31.50.

 

Then I see that it is a trick quetion as that has nothing to do with the question at all.

 

So to the equation C= 3.5 n^2

C=126

126 = 3.5 n^2 

dived both sides by 3.5

126 / 3.5 = 36             3.5(n^2) / 3.5 = (n^2)

36 = n^2

Take the square root of both sides

(6*6) = 36     (n*n)=(n^2)

6=n

n=6

Length of each side is 6 feet.