lg x + 4 lg y = -7,5 система lg x^2 - 4 lg x^3=30

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lgx + 4lgy = -7,5 lgx^2 - 4lgx^3 = 30 x > 0 y > 0 lgx^2 - 4lgx^3 = 30 => 2lgx - 12lgx = 30 | :2 lgx - 6lgx = 15 -5lgx = 15 lgx = -3 x = 10^(1/3) 4lgy = -7,5 - lgx 4lgy = -7,5 -(-3) = -7,5 +3 = -4,5 lgy = -4,5/4 = -1,125 = -9/8 y = 10^(8/9) c: