\(=a^3+b^3+c^3+3\left(a+b\right)\left(ab+ac+bc+c^2\right)\\ =a^3+b^3+c^3+3\left(a+b\right)\left(ab+c\left(a+b\right)+c^2\right)\\ =a^3+b^3+c^3+3ab\left(a+b\right)+3\left(a+b\right)^2c+3\left(a+b\right)c^2\\ =a^3+b^3=c^3+3a^2b+3ab^2+3\left(a+b\right)^2c+3\left(a+b\right)c^2\\ =\left(a+b\right)^3+3\left(a+b\right)^2c+3\left(a+b\right)c^2+c^3\\ =\left(a+b+c\right)^3\)
Ptđttnt:(a-b)^3-(b-c)^3+(c-a)^3
PTĐTTNT
(b-c)(b+c-2a)^3+(c-a)(c+a-2b)^2+(a-b)(a+b-2c)^3
PTĐTTNT: c(a + 2b)3 - b(2a + b)3
ptđttnt: a) ax2-ab+b-x
b) (a+b+c)3-a3-b3-c3
câu 1: GPT : (x + y)2 = (x + 1)*(y - 1 )
câu 2 : PTĐTTNT:
A = (x - y) 3 + ( y - z)3 + ( z - x ) 3
B = ( a + b+ c) - ( a3 + b3 +c3 )
PTĐTTNT:
a) \(\left(x^2+x\right)^2-2\left(x^2+x\right)-15\)
b) \(\left(a+b+c\right)^3-a^3-b^3-c^3\)
c) \(x-1+x^{n+3}-x^n\)
d) \(2x^4-7x^3-2x^2+13x+6\)
PTĐTTNT:
a) x^3+4x^2-29x+24
b) x^6+3x^5+4x^4+4x^3+4x^2+3x+1
c)x^12+1
ptđttnt : a, 9x^2y^3- 3x^4y^2- 6x^3y^2 + 18xy^4
b,7x^2y^2 - 21xy62z + 7xyz - 14xy
c,a^3x^2y - 5/2a63x^4 + 3/2a^4x^2y
PTĐTTNT bằng 3 cách
a)x^2+7x+12
b)3x^2-5x+2
c)x^2+9x-10
d)x^2-7x-8
e)2x^2+3x-5
