Hoặc
ĐS:
(a + b + c)3 = a3 + b3 + c3 + 3(a + b)(b + c)(c + a)
a, A =3(x – 1)2 - (x + 1)2 + 2(x – 3)(x + 3) – (2x + 3)2 - (5 – 20x) b, B = -x(x + 2)2 + (2x + 1)2 + (x + 3)(x2 - 3x + 9) – 1
a, 292 b, 62.58 c, 1022 d, 1013 e, 913 + 3.912 .9 + 3.91.92 + 93 f, 183 - 3.182 .8 + 3.18.82 - 2 g, 183+23 h, 233 - 27