Question

请问数学题：分解因式 A的立方加上3倍的A的平方减4

Answer 1

A^3+3A^2-4

=(A^3-A^2)+(4A^2-4)

=A^2(A-1)+4(A^2-1)

=A^2(A-1)+4(A+1)(A-1)

=(A-1)[A^2+4(A+1)]

=(A-1)(A^2+4A+4)

=(A-1)(A+2)^2