Factor this polynomial expression.
x^2- 12x + 36
A. (x – 6)(x-6)
B. (x + 9)(x-4)
C. (x+6)(x+6)
D. (x - 5)(x+6)

How to do this , and can some one explain

Prove that quadrilateral is a rhombus.

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.