(a-b)^2 = a^2 - 2ab + b^2 = (a^2 + 2ab + b^2) - 4ab = (a + b)^2 - 4ab
При a + b = 9, ab = −12:
9^2 + 4 * 12 = 81 + 48 = 129
(a-b)^2 = a^2 - 2ab + b^2 = (a^2 + 2ab + b^2) - 4ab = (a + b)^2 - 4ab
При a + b = 9, ab = −12:
9^2 + 4 * 12 = 81 + 48 = 129