⇔(2 x ) 2+2.2 x .1+1 2=0 ... c ,(3 x −4) 2−14(3 x −4)(6+3 x )+49(3 x +6)=16 ... ⇔9 x 2−24 x +16−126 x 2−252 x +168 x +336+147 x +294=16.
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\(-2x\left(6x-2\right)+3x\left(4x-7\right)=8\)
<=> \(-12x^2+4x+12x^2-21x=8\)
<=> \(-17x=8\)
<=> \(x=-\frac{8}{17}\)
\(\left(7x-2\right)\left(2x+3\right)-\left(3x-5\right)\left(4x+6\right)=2x^2-5\)
<=> \(14x^2+17x-6-12x^2+2x+30=2x^2-5\)
<=> \(14x^2+17x-6-12x^2+2x+30-2x^2+5=0\)
<=> \(19x+29=0\)
<=> \(19x=-29\)
<=> \(x=-\frac{29}{19}\)
Ý cuối mình k biết -22x2 là -22.2 hay -22x2 nữa :)
a, \(-2x\left(6x-2\right)+3x\left(4x-7\right)=8\)
\(\Leftrightarrow-12x^2+4x+12x^2-21x=8\)
\(\Leftrightarrow-17x=8\Leftrightarrow x=-\frac{8}{27}\)
b, \(\left(7x-2\right)\left(2x+3\right)-\left(3x-5\right)\left(4x+6\right)=2x^2-5\)
\(\Leftrightarrow2x^2+19x+24=2x^2-5\Leftrightarrow19x+29=0\Leftrightarrow x=-\frac{29}{19}\)