! ===7 red balls = 14 yuan ===7 red balls +2 blue balls = 7 red balls +3 blue balls 28 yuan = 7 red balls +4 blue balls 42 yuan = 7 red balls +5 blue balls 56 yuan = 7 red balls +6 blue balls 70 yuan = 7 red balls +7 blue balls 84 yuan = 7 red balls. 5438+00 blue ball = 140 yuan 7 red ball+1blue ball = 154 yuan 7 red ball+12 blue ball = 168 yuan 7 red ball+13 blue ball. 2 10 yuan 7 red ball+16 blue ball =224 yuan = = 8 red ball =56 yuan = = 8 red ball +2 blue ball =12 yuan 8 red ball +3 blue ball = 168 yuan 8 red ball +4. Red ball +8 blue ball =448 yuan 8 red ball +9 blue ball =504 yuan 8 red ball+10 blue ball = 560 yuan 8 red ball+1 1 blue ball =6 16 yuan 8 red ball+12 blue ball = 60. 38+05 blue ball = 8 red balls in 840 yuan+16 blue ball =896 yuan = = 9 red balls = 168 yuan = = 9 red balls +2 blue balls =336 yuan.