20x² + x - 12 = 0
D = b² - 4ac = 1 - 4×20×(-12)= 1 + 960 = 961 = 31²
x1 = ( - 1 + 31) / 40 = 30/40 = 0,75
x2 = ( - 1 - 31) / 40 = - 32/40 = - 0,8 - отрицательный корень.
<span><span>2a+27b²-12a²-3b (27b²-12a²)+(2а-3b) 3(9b²-4a²)+(2а-3b) </span> </span>
<span /><span><span>---------------------- = -------------------------- = -------------------------</span><span><span> = </span></span></span>
<span><span><span>2a</span>-3b 2a-3b 2a-3b </span></span>
<span><span /></span><span><span>3((3b-2a)(3b+2a))+(2а-3b) <span>(2a-3b)(-3(3b+2a)+1) (2a-3b)(-9b-6a+1)
</span></span><span>----------------------------------- = -------------------------- = -------------------------<span> = </span></span></span>
<span><span><span> 2a-3b 2a-3b 2a-3b </span></span></span>
<span><span><span>=-9b-6a+1 Вроде так. </span></span>
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