A+B+C+D Help gan sebenarnya soalnya itu doang tapi gara gara brainly nyuruh minimal 20 character ysudsh akhirnya aku tulis ini

[tex] \frac{6}{9} = \frac{6+c}{9+6} \\ \frac{2}{3} = \frac{6+c}{15} \\ 10 = 6+c \\ c = 4 \\ {} \\ \frac{6}{a} = \frac{6+c+5}{18} \\ \frac{6}{a} = \frac{15}{18} \\ a = 7,2 \\ {} \\ \frac{9}{a} = \frac{9+6}{b} \\ \frac{9}{7,2} = \frac{15}{b} \\ b = 12 \\ {} \\ \frac{9}{a} = \frac{9+6+d}{18} \\ \frac{9}{7,2} = \frac{15+d}{18} \\ 15+d = 22,5 \\ d = 7,5 \\ {} \\ a + b + c + d = 7,2 + 12 + 4 + 7,5 = 30,7 [/tex]