0.45 + x + 5/9 * 0.45x= 85
x + 5/9 * 9/20 *x = 85.00 - 0.45
x + 1/4 * x = 84.55
x + 0.25x = 84.55
1.25x = 84.55
x= 84.55 : 1.25
х= 67,64
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0,45 +67,64 +5/9 * 0,45 *67,64 = 85
68,09 + 5/9 * 30,438 = 85
68,09 + 5/9 * (15219/500) = 85
68,09 + [ (1*1691)/ (1*100) ] = 85
68.09 + 16.91 = 85
85=85