= 5/6 * 42/10х - 5/6 * 6/5у - 54/10 * 2/9х + 5,4 * 1,5у = 7/2х - у - 6/5х + 8,1у = (3,5х - 1,2х) + (8,1у - у) = 2,3х + 7,1у.
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