Question

Answer 1

Bài 10:

a: \(52^3=140608\)

b: \(499^3=124251499\)

c: \(48^3+6\cdot48^2+12\cdot48+8=\left(48+2\right)^3=125000\)

d: \(12^3-6\cdot12^2+144-9=999\)

Answer 2

Bài 9:

a: Ta có: \(M=8x^3+12x^2+6x+1\)

\(=\left(2x+1\right)^3\)

\(=50^3=125000\)

b: Ta có: \(N=\dfrac{x^3}{27}-\dfrac{x^2}{3}+x-1\)

\(=\left(\dfrac{1}{3}x-1\right)^3\)

\(=\left(\dfrac{1}{3}\cdot303-1\right)^3=1000000\)

c: Ta có: \(Q=\left(\dfrac{x}{y}+1\right)^3-15\left(\dfrac{x+y}{y}\right)^2+75\left(\dfrac{x-y}{y}+2\right)-125\)

\(=\left(\dfrac{x}{y}+1-5\right)^3\)

\(=\left(\dfrac{12}{2}-4\right)^3=2^3=8\)