(x-3)(x+7)-13=(x+8)(x-4)-2
x^2+7x-3x-21-13=x^2-4x+8x-32-2
x^2+4x-34=x^2+4x-34
0=0
x-любое
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<span>(2m+3)(4m²-6m+9)=</span>(2m+3)(2m-3)²
(√5+1)²+(√5+1)²=5+2√5+1+5-2√5+1=12;
<em>1/2x^2+3x+4=0 | * 2</em>
<em>x^2 + 6x + 8 = 0</em>
<em>D = b^2-4ac = 6^2 - 4*8 = 36-32 = √4 = 2^2</em>
<em>x1= (-b+√D)/2a = (-6+2)/2=-4/2= -2</em>
<em>x2= (-b - √D)/2a = (-6-2)/2=-8/2= -4</em>
<em>Ответ: x1 = - 2, x2 = -4</em>