Factor the following polynomial completely. 5x^4 + 20x^3 – 105^2
OA. 5x2(x + 3)(x – 7)
OB. 5x2(x − 3)(x + 7)
OC. 5x3(x – 3)(x + 7)
OD. 5x3(7 + 3)(x – 7)

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.