Question

(x2 +12)/(x-3) = (7x)/(x-3) срочно через дискреминант ​

Answer 1

Ответ:

$x_1=4; x_2=3$

Объяснение:

$frac{x^2+12}{x-3}=frac{7x}{x-3}|*(x-3)\x^2+12=7x\x^2-7x+12=0\D=49-4*12=1\x_1=frac{7+1}{2}=4\x_2=frac{7-1}{2}=3$

Answer 2

$( {x}^{2} + 12 )times (x - 3) = 7x times (x - 3) \ {7x}^{2} - 21x = {x}^{3} - {3x}^{2} + 12x - 36 \ {7x}^{2} - 21x - {x}^{3} + {3x}^{2} - 12x + 36 = 0 \ - {x}^{3} + {10x}^{2} - 33x + 36 = 0 \ { - x}^{3} + {3x}^{2} + {7x}^{2} - 21x - 12x + 36 = 0 \ - (x - 3) times ( {x}^{2} - 7x + 12) = 0 \ - (x - 3) times (x - 3)(x - 4) = 0 \ {(x - 3)}^{2} times (x - 4) = 0 \ x1 = 3 \ x2 = 4$