x-3x(1-12x)=11-(5-6x)(6x+5)

$x-3x(1-12x)=11-(5-6x)(6x+5)$

$x-3x(1-12x)=11-(5-6x)(5+6x)$

$x-3x+36x^{2}=11-(25-36x^{2})$

$x-3x+36x^{2}=11-25+36x^{2}$

$11-25+36x^{2}-x+3x-36x^{2}=0$

$(36x^{2}-36x^{2})+(3x-x)+(11-25)=0$

$2x-14=0$

$2x=14$

$x=14:2$

$x=7$

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$7-3\cdot7\cdot(1-12\cdot7)=11-(5-6\cdot7)\cdot(6\cdot7+5)$ (это проверка)

$7-21\cdot(1-84)=11-(5-42)\cdot(42+5)$

$7-21\cdot(-83)=11-(-37)\cdot47$

$7+1743=11+37\cdot47$

$1750=11+1739$

$1750=1750$