Question

Решите уравнение: x+7=8/x решите

Answer 1

$\ x + 7 = frac{8}{x} |*x \ \ x^2 + 7x = 8 \ \x^2 + 7x - 8 = 0 \ \D = (-7)^2 - 4*(-8) = 49+32 = 81 \ \ sqrt{81} = 9 \ \x_1 = (-7+9)/2 = 1 \ \x_2 = (-7-9) / 2 = -8$