one bubble question [8.06] Sam decides to build a square garden. If the area of the garden is 4x2 − 20x + 25 square feet, what is the length of one side of the garden?

(5x + 2) feet
(5x − 2) feet
(2x + 5) feet
(2x − 5) feet

Question

one bubble question  	[8.06] Sam decides to build a square garden. If the area of the garden is 4x2 − 20x + 25 square feet, what is the length of one side of the garden?
 	
	(5x + 2) feet
	(5x − 2) feet
	(2x + 5) feet
	(2x − 5) feet

amorfide · Answer

you just want to solve the quadratic, either factorise or use the quadratic formula

$$x=\frac{ -b \pm \sqrt{  b^{2}-4ac } }{ 2a}$$

where a standard quadratic is in the form

$$ax^{2}+bx+c$$

so in your case, 
a=4
b=-20
c=25

solve for x and you get your answer