a, BT = (x + 4)3 = 103 = 1000
b, BT = (x - 2)3 = 203 = 8000
c, BT = (x + 1)3 = 1003 = 1000000
d, BT = (x - 3)3 = 23 = 8
e, BT = (x + 2)3 = 503 = 125000
f, BT = (3x - 2y)3 = (3.4 - 6.2)2 = 0
g, Đặt \(\dfrac{x}{2}-y=a\) Ta có BT = a3 - 6a2 - 12a - 8 (ko phải hằng đăng thức chắc đề sai)
a: \(x^3+12x^2+48x+64=\left(x+4\right)^3\)
\(=10^3=1000\)
b: \(x^3-6x^2+12x-8=\left(x-2\right)^3\)
\(=20^3=8000\)
c: \(x^3+3x^2+3x+1=\left(x+1\right)^3\)
\(=100^3=1000000\)
d: \(x^3-9x^2+27x-27=\left(x-3\right)^3\)
\(=2^3=8\)
e: \(x^3+6x^2+12x+8=\left(x+2\right)^3\)
\(=50^3=125000\)
f: \(27x^3-54x^2y+36xy^2-8y^3=\left(3x-2y\right)^3\)
\(=\left(3\cdot4-2\cdot6\right)^3=0\)
g: \(\left(\dfrac{x}{2}-y\right)^3-6\left(y-\dfrac{x}{2}\right)^2+12\left(y-\dfrac{x}{2}\right)-8=\left(y-\dfrac{x}{2}-2\right)^3\)
\(=\left(1-103-2\right)^3\)
\(=-104^3=-1124864\)
h: \(x^3-3x^2+3x-1=\left(x-1\right)^3\)
\(=100^3=1000000\)
i: \(\left(x+y\right)^3-9\left(x+y\right)^2+27\left(x+y\right)-27=\left(x+y-3\right)^3\)
\(=\left(2+6-3\right)^3=5^3=125\)
j: \(27x^3z^6-54x^2yz^4+36xy^2z^2-8y^3=\left(3xz^2-2y\right)^3\)
\(=\left(3\cdot25\cdot4-2\cdot150\right)^3\)
=0
k: \(8m^3+12m^2+6m+1=\left(2m+1\right)^3\)
\(=50^3=125000\)
