Which of the following is an example of the difference of two squares? x2−9x2−9 (x−9)2 x3−9x3−9 (x+9)2

 x²−9

Step-by-step explanation:

A square number is obtained ehen we multiply a number to itself.

For example: 5 × 5 = 5² = 25 [It is a square number]

We can do this in expression too, For example: z×z =z²

From all the given options, only x²−9 has both terms as square.

∵ x² = x × x

and 9 = 3×3= 3²

So that,  x²−9  =(x)²-(3)²

Hence, the correct option is x²−9.

for any of you who need the translation here it is

step-by-step explanation:

find the angular size of the equatorial radius of the earth, if the horizontal parallax of the sun