Question

Найдите корень уравнения х^2+9=(х+9)^2.

Answer 1

x^2+9=x^2+18x+81

18x+81-9=0

18x+72=0

18x=-72

x=-72/18

x=-4

Answer 2

(x+9)² - x² = 9

(x + 9 - x)(x + 9 + x) = 9

9(2x + 9) = 9

2x + 9 = 1

2x = -8

x = -4