Question

(x^2-81)^2+(x^2+7x-18)^2=0 долго думал. помогите пожалуйста

Answer 1

$( {x}^{2} - 81) ^{2} + {( {x}^{2} + 7x - 18)}^{2} = 0 \\ ((x - 9)(x + 9))^{2} + {((x + 9)(x - 2))}^{2} = 0 \\ {(x - 9)}^{2} {(x + 9)}^{2} + {(x + 9)}^{2} {(x - 2)}^{2} = 0 \\ {(x + 9)}^{2} ( {(x - 9)}^{2} + {(x - 2)}^{2} ) = 0$

$(x + 9) ^{2} = 0 \\ x = - 9$

(x-9)²+(x-2)²=0
x²-18x+81+x²-4x+4=0
2x²-22x+85=0
нет корней
Ответ: x = -9