2d 15Erek Erek 15 pada buku seribu tafsir mimpi 2D 3D 4D bergambar dan primbon melambangkan seorang hakim, sedangkan kode alam angka 15 adalahRewrite 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