Đáp án:
Giải thích các bước giải:
Áp dụng: `a(b+-c)=ab+-ac`
`=>2(x-1)=2x-2`
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$2\left(x-1\right)^2-4\left(3+x\right)^2+2x\left(x+5\right)$
$=2x^2-4x+2-4\left(9+6x+x^2\right)+2x\left(x+5\right)$
$=2x^2-4x+2-36-24x-4x^2+2x\left(x+5\right)$
$=2x^2-4x+2-36-24x-4x^2+2x^2+10x$
$=-18x-34$
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$2\left(2x+5\right)^2-3\left(4x+1\right)\left(1-4x\right)$
$=8x^2+40x+50-3\left(4x+1\right)\left(1-4x\right)$
$=8x^2+40x+50-3+48x^2$
$=56x^2+40x+47$
