Решите 3 уравнения плиз!!!!! (распишите подробно) а)x+|x|+7x+12=0 б)-2x^2+6/x+6=11x/6+x...

$a) x+|x|+7x+2=0$
$8x+|x|+12=0$
$8x+x+12=0,x \geq 0$
$8x-x+12=0, x\ \textless \ 0$
$x=- \frac{4}{3} ,x \geq 0$
$x=- \frac{12}{7} ,x\ \textless \ 0$
x∈∅
$x=- \frac{12}{7}$
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в) $x^4+3x^2-10=0$
$x^2=t$
$t^2+3t-10=0$
$D=9+40= \sqrt{49} = 7^2$
$t_{1} =2$
$t_{2} =-5$
$x^2=t$
$x^2=2$
$x^2=-5$ x∉R
$x_{1} = \sqrt{2}$
$x_{2} =- \sqrt{2}$
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