(x+7)(x-7)+(x-3)²=53. Решите уровнение

Question

(x+7)(x-7)+(x-3)²=53. Решите уровнение

Answer 1

(x + 7)(x - 7) + ( x - 3)² = 53
x² - 49 + (x - 3)(x - 3) = 53
x² - 49 + x² - 6x + 9 - 53 = 0
2x² - 6x - 93 =0
D = b² - 4ac = (-6)² - 4 × 2 × ( - 93) = 36 + 744 = 780
x₁,₂ = 6 ⁺/⁻√780/4