2, 3, 4, 5, 6, 7, 8 всего 7 чисел
16a^2 + 8a + 1 - 2(4a - 8a^2 + 1 - 2a) + (1 - 4a + 4a^2) =
= 16a^2 + 8a + 1 - 8a + 16a^2 - 2 + 4a + 1 - 4a + 4a^2 =
= 36a^2
a = - 2,5
36*(-2,5)^2 = 225
!!!!!!!!!!!!!!!!!!!!!!!!!!!
48- 6x-5=4-7x
48-6x-5-4+7x=0
39+x=0
X=-39