Question

tính:

(2x+3/2)³

Answer 1

\(=8x^3+3\cdot4x^2\cdot\dfrac{3}{2}+3\cdot2x\cdot\dfrac{9}{4}+\dfrac{27}{8}\)

\(=8x^3+18x^2+\dfrac{27}{2}x+\dfrac{27}{8}\)

Answer 2

\(\left(2x+\dfrac{3}{2}\right)^3=\left(2x\right)^3+3.\left(2x\right)^2.\dfrac{3}{2}+3.2x.\left(\dfrac{3}{2}\right)^2+\left(\dfrac{3}{2}\right)^3\\ =8x^3+18x^2+\dfrac{27}{2}x+\dfrac{27}{8}\)