Question

 Bài 1:  Làm tính nhân:

                      a. 3x²(5x²- 4x +3)                                            b. – 5xy(3x²y – 5xy +y²)  

                      c. (5x²- 4x)(x -3)                                             d. (x – 3y)(3x² + y² +5xy)

Answer 1

a, \(15^4-12x^3+9x^2\)

b,\(-15x^3y^2+25x^2y^2-5xy^3\)

c, \(5x^3-19x^2+12x\)

d, 

x3+xy2+5x2y−9x2y−3y3−15xy2=3x3−3y3−14xy2−4x2y

Answer 2

\(a,=15x^4-12x^3+9x^2\\ b,=-15x^3y^2+25x^2y^2-5xy^3\\ c,=5x^3-15x^2-4x^2+12x=5x^3-19x^2+12x\\ d,=3x^3+xy^2+5x^2y-9x^2y-3y^3-15xy^2=3x^3-14xy^2-4x^2y-3y^3\)