а) 20+15+11+10+25+20+10+15+18/9=16
б)Мо=20, Ме=25
1.21 - 7Х = 4X
1.21 = 4X + 7X
1.21 = 11 X
X = 0.11
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1.21 - 4X = 7X
1.21 = 7X + 4X
1.21 = 11X
92*(х:109+4924)=467 360.