Question

разложите на множители квадратный трехчлен x2-18x+45=0

Answer 1

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х² - 18х + 45 = 0

ax² + bx + c = 0

D = b² - 4•a•c = (-18)² - 4•1•45 = 324 - 180 = 144 = 12²

x = ( - b ± √D )/2a = ( 18 ± 12 )/2 = 9 ± 6

x₁ = 9 - 6 = 3

x₂ = 9 + 6 = 15

ax² + bx + c = a•( x - x₁ )( x - x₂ )

x² - 18x + 45 = ( x - 3 )( x - 15 )

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