2d 15Rewrite d^ Rewrite d^ Rewrite d^ {2}-2d-15 as left (d^ {2}-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-2d-15 as left (d^ Rewrite d^ {2}-2d-15 as left (d^ {2}-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-2d-15 as left (d^ Rewrite d^ Rewrite d^ {2}-2d-15 as left (d^ {2}-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-2d-15 as left (d^ Rewrite d^ {2}-2d-15 as left (d^ {2}-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations ofRewrite d^ {2}-2d-15 as left (d^ {2}-5drht)+left (3d-15rht). Factor out d in the first and 3 in the second group. Factor out common term d-5 by using distributive property. All equations of